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Abstract:

The present invention provides systems and methods for deploying
implantable devices within the body. The delivery and deployment systems
include at least one catheter or an assembly of catheters for selectively
positioning the lumens of the implant to within target vessels. Various
deployment and attachment mechanisms are provided for selectively
deploying the implants.

Claims:

1. A stent-loaded catheter assembly comprising:a catheter having at least
one lumen; anda stent comprising a main lumen having a proximal end and a
distal end and at least one side branch lumen connected to and extending
laterally from the main lumen, wherein the a distal end of the catheter
is positioned within the side branch lumen; anda string extending through
the at least one catheter lumen and releasably attached to a distal end
of the side branch lumen, wherein, prior to release of the string from
the side branch lumen, selective movement of the catheter at a proximal
end results in a corresponding pivotal movement at the distal end wherein
the catheter distal end is steerable.

2. The stent-loaded catheter assembly of claim 1, wherein the selective
movement is axial translation and the pivotal movement is forward and
backwards.

3. The stent-loaded catheter assembly of claim 1, wherein the selective
movement is rotational and the pivotal movement is lateral.

4. The stent-loaded catheter assembly of claim 2, further comprising a
mechanism for selectively tensioning the string to selectively increase
and selectively reduce a profile of the side branch lumen.

5. The stent-loaded catheter assembly of claim 1, wherein the ends of the
string each extend through a separate lumen within the catheter and a
central portion is weaved through apices of a distal end of the at least
one side branch lumen.

6. A stent-loaded catheter assembly comprising:a catheter having at least
one lumen; anda stent comprising a main lumen having a proximal end and a
distal end and at least one side branch lumen connected to and extending
laterally from the main lumen, wherein the catheter lumen is adapted for
receiving the stent in a reduced profile; anda pin assembly engaging
apices of a distal end of the main lumen wherein the pin assembly is
spring-loaded wherein, upon release of the spring-load, the pin assembly
releases the apices.

7. A system for delivering and deploying a stent having a distal end and a
proximal end and a structure therebetween wherein the structure having an
initial profile which is reducable along a length of the structure, the
system comprising:a catheter having an inner diameter less than a
diameter of the stent in the initial profile, the catheter adapted for
receiving the stent in a reduced profile; anda lumen comprising a port
for receiving a fluid and at least one gasket distal of the port prevent
leakage of the fluid from the port, wherein at least a portion of the
catheter is flushed by passage of the fluid therethrough.

8. A sheath adapted for endovascular delivery of catheters, the sheath
comprising:a braided material embedded within a wall of the sheath and
extending along a length of tile sheath; andat least one solder joint
within the braided material.

9. The sheath of claim 8, comprising a plurality of spaced apart solder
joints along the length the of the braided material.

10. A stent-loaded catheter assembly comprising:a catheter sheath having
at least one lumen and at least one radiopaque marking; anda stent device
comprising a main lumen having a proximal end and a distal end and at
least one side branch lumen connected to and extending laterally from the
main lumen, wherein the catheter lumen is adapted for receiving the stent
device in a reduced profile; andthe stent device further having at least
one selectively positioned radiopaque marking, wherein alignment of the
radiopaque marking on the stent device with the radiopaque marking on the
catheter sheath validates proper loading of the stent device within the
catheter sheath.

11. The stent-loaded assembly of claim 10, wherein the catheter sheath has
two radiopaque markings extending along its length and spaced 180.degree.
apart from each other; and the stent device has two radiopaque markings
extending along its length and spaced 180.degree. apart from each other.

12. The stent-loaded assembly of claim 10, wherein the stent device
comprises a stent and graft engaged with the stent; and wherein the at
least one radiopaque marking on the stent device is on the graft.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001]The present application is a continuation of U.S. patent application
Ser. No. 12/029,180 filed Feb. 11, 2008 which is a non-provisional of
U.S. Provisional Patent Application No. 60/889,186, filed on Feb. 9,
2007, the content of each of which is incorporated herein by reference in
its entirety.

FIELD OF THE INVENTION

[0002]The present invention relates to the treatment of vascular disease,
including for example aneurysms, ruptures, psuedoaneurysms, dissections,
exclusion of vulnerable plaque and treatment of occlusive conditions, and
more particularly, the invention is related to an apparatus and method
for delivering and deploying an implantable device within the body to
treat such conditions. The present invention is particularly suitable for
implanting stents, grafts and stent grafts within arteries or other
vessels at sites involving two or more intersecting vessels.

BACKGROUND OF THE INVENTION

[0003]It is well known in the prior art to treat vascular disease with
implantable stents and grafts. For example, it is well known in the art
to interpose within a stenotic or occluded portion of an artery a stent
capable of self-expanding or being balloon-expandable. Similarly, it is
also well known in the prior art to use a graft or a stent graft to
repair highly damaged or vulnerable portions of a vessel, particularly
the aorta, thereby ensuring blood flow and reducing the risk of an
aneurysm or rupture.

[0004]A more challenging situation occurs when it is desirable to use a
stent, a graft or a stent graft at or around the intersection between a
major artery (e.g., the abdominal aorta) and one or more intersecting
arteries (e.g., the renal arteries). Use of single axial stents or grafts
may effectively seal or block-off the blood flow to collateral organs
such as the kidneys. U.S. Pat. No. 6,030,414 addresses such a situation,
disclosing use of a stent graft having lateral openings for alignment
with collateral blood flow passages extending from the primary vessel
into which the stent graft is positioned. The lateral openings are
pre-positioned within the stent based on identification of the relative
positioning of the lateral vessels with which they are to be aligned.
U.S. Pat. No. 6,099,548 discloses a multi-branch graft and a system for
deploying it. Implantation of the graft is quite involved, requiring a
discrete, balloon-deployable stent for securing each side branch of the
graft within a designated branch artery. Additionally, a plurality of
styles is necessary to deliver the graft, occupying space within the
vasculature and thereby making the system less adaptable for implantation
into smaller vessels. Further, delivery of the graft and the stents
requires access and exposure to each of the branch vessels into which the
graft is to be placed by way of a secondary arteriotomy. These
techniques, while effective, may be cumbersome and somewhat difficult to
employ and execute, particularly where the implant site involves two or
more vessels intersecting the primary vessel, all of which require
engraving.

[0005]The use of bifurcated stents for treating abdominal aortic aneurysms
(AAA) is well known in the art. These stents have been developed
specifically to address the problems that arise in the treatment of
vascular defects and or disease at or near the site of a bifurcation. The
bifurcated stent is typically configured in a "pant" design which
comprises a tubular body or trunk and two tubular legs. Examples of
bifurcated stents are provided in U.S. Pat. Nos. 5,723,004 and 5,755,735.
Bifurcated stents may have either unitary configurations or modular
configurations in which die components of the stent are interconnected in
situ. In particular, one or both of the leg extensions are attachable to
a main tubular body. Although the delivery of modular systems is less
difficult due to the smaller sizes of the components, it is difficult to
align and interconnect the legs with the body lumen with enough precision
to avoid any leakage. On the other hand, while unitary stents reduce the
probability of leakage, their larger structure is often difficult to
deliver to a treatment site having a constrained geometry.

[0006]The highly curved anatomy of the aortic arch requires a stent that
can accommodate various radii of curvature. More particularly, the stent
wall is required to be adaptable to the tighter radius of curvature of
the underside of the aortic arch without kinking while being able to
extend or stretch to accommodate the longer topside of the arch without
stretching the stent cells/wire matrix beyond its elastic capabilities.

[0007]Additionally, the variability of the anatomy of the aortic arch from
person to person makes it a difficult location in which to place a stent
graft. While the number of branch vessels originating from the arch is
most commonly three, namely, the left subclavian artery, the left common
carotid artery and the innominate artery, in some patients the number of
branch vessels may be one, more commonly two and in some cases four, five
or even six. Moreover, the spacing and angular orientation between the
tributary vessels are variable from person to person.

[0008]Still yet, placing stents/grafts within the aortic arch presents
additional challenges. The arch region of the aorta is subject to very
high blood flow and pressures which make it difficult to position a stent
graft without stopping the heart and placing the patient on
cardiopulmonary bypass. Moreover, even if the stent graft is able to be
properly placed, it must be secured in a manner to endure the constant
high blood flow, pressures, and shear forces it is subjected to over time
in order to prevent it from migrating or leaking. Additionally, the aorta
undergoes relatively significant changes (of about 7%) in its diameter
due to vasodilation and vasorestriction. As such, if an aortic arch graft
is not able to expand and contract to accommodate such changes, there may
be an insufficient seal between the graft and the aortic wall, subjecting
it to a risk of migration and/or leakage.

[0009]In order to achieve alignment of a side branch stent or a lateral
opening of the main stent with a branch vessel, a custom stent designed
and manufactured according to each patient's unique geometrical
constraints would be required. The measurements required to create a
custom manufactured stent to fit the patient's unique vascular anatomy
could be obtained using spiral tomography, computed tomography (CT),
fluoroscopy, or other vascular imaging system. However, while such
measurements and the associated manufacture of such a custom stent could
be accomplished, it would be time consuming and expensive. Furthermore,
for those patients who require immediate intervention involving the use
of a stent, such a customized stent is impractical. In these situations
it would be highly desirable to have a stent which is capable of
adjustability in situ while being placed. It would likewise be highly
desirable to have the degree of adjustability sufficient to allow for a
discrete number of stents to be manufactured in advance and available to
accommodate the required range of sizes and configurations encountered.

[0010]Another disadvantage of conventional stents and stent grafts is the
limitations in adjusting the position of or subsequently retrieving the
stent or stent-graft once it has been deployed. Often, while the stent is
being deployed, the final location of the delivered stent is determined
not to be optimal for achieving the desired therapeutic effect. During
deployment of self-expanding stents, the mode of deployment is either to
push the stent out of a delivery catheter, or more commonly to retract an
outer sheath while holding the stent in a fixed location relative to the
vasculature. In either case the distal end of the stent is not attached
to the catheter and, as such, is able to freely expand to its maximum
diameter and seal with the surrounding artery wall. While this
self-expanding capability is advantageous in deploying the stent, it
presents the user with a disadvantage when desiring to remove or
reposition the stent. Some designs utilize a trigger wire(s) to retain
the distal end of the stent selectively until such time as full
deployment is desired and accomplished by releasing the "trigger" wire or
tether wire(s). The limitation of this design is the lack of ability to
reduce the diameter of the entire length of stent. The significance of
not be able to reduce the diameter of the stent while positioning it is
that the blood flow is occluded by the fully expanded main body of the
stent even though its distal end is held from opening.

[0011]Another disadvantage of conventional stent-grafts is the temporary
disruption in blood flow through the vessel. In the case of balloon
deployable stents and stent-grafts, expansion of the balloon itself while
deploying the stent or stent-graft causes disruption of blood flow
through the vessel. Moreover, in certain applications, a separate balloon
is used at a location distal to the distal end of the stent delivery
catheter to actively block blood flow while the stent is being placed. In
the case of self-expanding stent-grafts, the misplacement of a stent
graft may be due to disruption of the arterial flow during deployment,
requiring the placement of an additional stent-graft in an overlapping
fashion to complete the repair of the vessel. Even without disruptions in
flow, the strong momentum of the arterial blood flow can cause a
partially opened stent-graft to be pushed downstream by the high-pressure
pulsatile impact force of the blood entering the partially deployed stent
graft.

[0012]Attempts have been made to address some of the above-described
disadvantages of conventional stents and stent grafts. For example, U.S.
Pat. No. 6,099,548 discloses the use of strings passed through and
attached to the distal end of the stent which is inserted through a first
opening in the vasculature. The string ends are then passed through a
second opening in the vasculature such that they can be pulled, thereby
moving the stent within the vasculature. While the use of attached
strings provides some additional control of the stent's placement, one
skilled in the art can appreciate that passing strings from within the
vasculature through a second opening presents procedural difficulties.
Moreover, it is advantageous to the welfare of the patient to minimize
the number of surgical openings when performing any procedure.

[0013]With the limitations of current stent grafts and stent graft
placement technologies, there is clearly a need for an improved means and
method for implanting a stent or graft and for treating vascular disease
and conditions affecting interconnecting vessels (i.e., vascular trees)
which address the drawbacks of the prior art.

SUMMARY OF THE INVENTION

[0014]The present invention provides implantable devices, and systems and
methods for deploying the implantable devices within the body.

[0015]The implant sites addressable by the subject devices may be any
tubular or hollow tissue lumen or organ; however, the most typical
implant sites are vascular structures, particularly the aorta. Thus,
devices of the invention are constructed such that they can address
implant sites involving two or more intersecting tubular structures and,
as such, are particularly suitable in the context of treating vascular
trees such as the aortic arch and the infrarenal aorta. As such, the
implantable devices generally include a tubular member or lumen, most
typically in the form of a stent, a graft or a stent graft, where the
devices may further include one or more branching or transverse tubular
members or lumens laterally extending from the main or primary tubular
member.

[0016]The devices and their lumens are formed by interconnected cells
where the cells are defined by struts which are preferably made of an
elastic or superelastic material such that changes and adjustments can be
made to various dimensions, orientations and shapes of the device lumens.
As such, another feature of the present invention involves the reduction
or expansion of a dimension, e.g., diameter and length, of one or more
the device lumens. Typically, a change in one dimension is dependent upon
or results in an opposite change in another dimension, i.e., when the
diameter of the stent lumen is reduced, the length of the stent
increases, and visa versa. The material construct of the devices further
enables the one or more side branch lumens of the devices to be
positioned at any appropriate location along the length of the main lumen
and at any angle with respect to the longitudinal axis of the main lumen.
Where there are two or more side branch lumens, the lumens may be spaced
axially and circumferentially angled relative to each other to
accommodate the target vasculature into which the implant is to be
placed.

[0017]The systems of the present invention are particularly suitable for
delivering and deploying the subject stent, graft or stent graft devices
within a vessel or tubular structure within the body, particularly where
the implant site involves two or more interconnecting vessels. In
general, the delivery and deployment systems of the present invention
enables independent control of each lumenal end of an implantable device,
where "control" may involve one or more acts of delivering, positioning,
placing, lengthening, foreshortening, expanding, and reducing a dimension
of the device. The systems further include means for partially and/or
fully deploying the implantable devices as well as repositioning the
devices subsequent to at least partial deployment within the vasculature.

[0018]Such independent control and deployment capabilities are provided by
the utilization of at least one element or member associated with the
delivery system and releasably attached to each lumenal end. Each member
is independently manipulatable relative to the other releasably attached
members. As such, each lumenal end of the implantable device may be
individually and independently deployed as desired, where some or all of
the lumenal ends may be simultaneously deployed or they may be serially
deployed in any order that best facilitates the implantation procedure.

[0019]In one variation, the elements include a collection of elongated
members used to deploy the implantable devices where the elongated
elements may take any suitable form including but not limited to strings,
lines, filaments, fibers, wires, stranded cables, tubings, etc. where at
least one elongated member is releasably attached to one, some or all of
the lumenal ends of the implantable device. In one particular embodiment,
a collection of strings is employed where a single string is provided for
and used to control each of the proximal and distal ends of the main
lumen and for each side branch lumen of the implantable device. In
another embodiment, a set of strings is used for each lumenal end, where
each set includes one string per apex of the device ends. The subject
delivery systems include means for selectively tensioning or pulling each
of the single or plurality of attachment strings or elongate members
whereby the implantable device is selectively deployable by releasing the
tension on the attachment strings.

[0020]In still other embodiments, something other than a string(s) or
elongated member(s) is used to control and retain at least one of the
lumenal ends. In one particular embodiment, the retention mechanism
comprises a set of extensions, such as pins or hooks, extending from the
distal end of a catheter or guidewire be associated with the delivery
system. The extensions are used to engage the apices of a lumenal end in
a releasable fashion to retain that lumenal end in an undeployed state.
The extension members may be used in conjunction with a receptacle or the
like which receives the ends of the members when the apices are
"captured" by the retention.

[0021]There may be other means equally suitable for selective deployment
of the implantable devices beyond the use of detachable strings. For
example, similar to the use of detachable coils used in aneurysm repair,
a current may be used to erode by electrolysis the connection point to
the stent ends to facilitate a controlled release and deployment of the
stent. Other means of releasable attachment which may be employed with
the delivery systems to deploy the subject devices include but are not
limited to thermal energy, magnetic means, chemical means, mechanical
means or any other controllable detachment means. Irrespective of the
type of deployment techniques used, selective deployment allows the
implantable device to be partially deployable or deployable in increments
or sections, where the implant may be entirely or partially exposed from
the delivery system without being fully released/deployed at the implant
site.

[0022]The implant delivery and deployment system in one embodiment
includes a series of guidewires, a distal catheter portion and a proximal
handle portion where the implantable device is loaded within the catheter
portion prior to delivery to the target site. At least the catheter
portion of the system is tracked over the one or more guidewires which
direct and position the stent or stent-graft and each of its branches
within their respective targeted vessels selected for implantation.
Various controls are provided for the selective tensioning and release of
the implant's luminal ends, where the controls may be located on the
handle portion, the catheter portion or both. In a preferred embodiment,
the catheter portion and/or the delivery guidewires are articulatable at
their distal ends to facilitate navigation through the vasculature.

[0023]One embodiment of the system includes an articulating delivery
guidewire or guiding catheter. The articulating guidewire may have one or
more articulation points to allow an operator to change the shape of the
distal portion of the guidewire by manipulation of the proximal portion
of the guidewire. The guidewire can be preconfigured to change from a
straight configuration into a range of various preselected shapes brought
about by controlling individual articulation points during manipulation
of the proximal portion of the guidewire. In this way, a guidewire may be
produced to unique specifications for access to distinct areas of the
vasculature. For example, this may be of particular importance in
locating the implant within a region that requires an "S" shaped path
from entry point to implant target site. Introduction of a guidewire
through a femoral artery access point leading to an implant target in the
innominate artery exemplifies one instance of a potentially difficult "S"
shaped navigation pathway where such an articulating guidewire may be
advantageous.

[0024]The methods of the present invention involve deploying the
implantable device where certain of the methods involve the use of the
subject systems. Methods for manufacturing the implantable devices are
also provided.

[0025]Another objective of the invention is to provide a method of stent
deployment which does not cause temporary occlusion of the vessel into
which stent is to be placed.

[0026]Another objective of the invention is to provide a method of stent
deployment using guidewires and an associated delivery system which enter
the vasculature from a single access location.

[0027]An advantage of the stent delivery system of the present invention
is that it does not require the use of space-occupying stylets and
balloon catheters.

[0028]Another advantage of the subject system is that it allows for
adjustment of the position or placement, as well as removal, of a stent
during and after deployment thereof.

[0029]The present invention is additionally advantageous in that it
provides a user with the ability to deploy a stent, to evaluate the
suitability of the resulting deployment using standard imaging, such as
by use of radiographic dye and fluoroscopy or any other imaging system,
to check for endoleak between the covered stent wall and the surrounding
arterial wall and to detach the stent from the delivery system upon
adequate stent deployment or, in the case of an inadequate deployment, to
either relocate the stent to a new location and obtain a satisfactory
result by controlling the delivery and detachment of the stent in a
repeatable manner, or to remove the stent entirely.

[0030]The present invention is additionally advantageous in that it
secures the stent from migration within the vasculature by integrating
the cells of the side branch lumen into the cells of the main body lumen
such that, when the side branch lumens are deployed within their branch
vessels, the main body lumen is constrained from migration by a "lock and
key" mechanism. More specifically, the interconnection of the side branch
lumen to the main body lumen is accomplished by forming the side branch
lumen and the main body lumen from the same single wire where a specific
wire wrap pattern is used to form a linking mesh to integrate the side
branch lumen with the main lumen. Thus, when the side branch is deployed
within and held in place by the side branch artery, the main body of the
stent cannot migrate. Moreover, such a "passive" anchoring mechanism is
atraumatic, as opposed to an active anchoring means, such as barbs or
hooks, which may damage the cellular structures of the implant site
leading to smooth muscle proliferation, restenosis, and other vascular
complications.

[0031]These and other objects, advantages, and features of the invention
will become apparent to those persons skilled in the art upon reading the
details of the invention as more fully described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032]The invention is best understood from the following detailed
description when read in conjunction with the accompanying drawings. It
is emphasized that, according to common practice, the various features of
the drawings are not to-scale. On the contrary, the dimensions of the
various features are arbitrarily expanded or reduced for clarity. Also
for purposes of clarity, certain features of the invention may not be
depicted in some of the drawings. Included in the drawings are the
following figures:

[0033]FIG. 1A illustrates an embodiment of an implant of the present
invention in a natural, deployed state. FIG. 1B illustrates another
embodiment of an implant of the present invention in a natural, deployed
state. FIG. 1c illustrates another embodiment of an implant in which the
side branch lumens are angled. FIG. 1D illustrates an end view of the
implant of FIG. 1c. FIG. 1E illustrates another embodiment of an implant
of the present invention having a cardiac valve operatively coupled to
it.

[0034]FIG. 2A is a perspective view of a system of the present invention
for delivering and deploying the implants of the present invention within
a tubular tissue structure within the body. FIG. 2B is an enlarged
perspective view of the portion of the system of FIG. 2A including a side
branch control and catheter hubs.

[0035]FIGS. 3A and 3B are side views of the side branch control and
catheter hubs of the system of FIGS. 2A and 2B in open and closed
configurations, respectively.

[0036]FIG. 4 is a side view of the handle portions of the system of FIG.
2A.

[0037]FIG. 5A is a side view of the distal end of the delivery and
deployment system of the present invention with an implantable device of
the present invention shown partially deployed from the implantation
system. FIG. 5B shows a top view of the system and implantable device of
FIG. 5A. FIG. 5c shows a longitudinal cross-sectional view of FIG. 5B.

[0038]FIG. 6A is a cross-sectional view taken along line A-A of FIG. 5c.
FIG. 6B is a cross-sectional view taken along line B-B of FIG. 5c. FIG.
6C is longitudinal cross-sectional view of the catheter tip portion of
the delivery and deployment system of FIG. 5c.

[0039]FIGS. 7A, 7B and 7C are cross-sectional views of possible
embodiments of side branch catheters of the present invention.

[0040]FIGS. 8A-8H illustrate various steps of a method of the present
invention for delivering a stent of the present invention using an
implantation system of the present invention.

[0041]FIG. 9 illustrates another embodiment of handle portion of the
delivery and deployment system of the present invention.

[0042]FIG. 10A illustrates a side view of an embodiment of an inner member
of the catheter portion of the delivery and deployment system of the
present invention. FIG. 10B illustrates a cross-sectional view of the
inner member of FIG. 10A taken along the line B-B of FIG. 10A. FIG. 10c
illustrates a cross-sectional view of the inner member of FIG. 10 taken
along the line C-C of FIG. 10A.

[0043]FIG. 11 illustrates the partial deployment of the implant of FIG. 1E
within the aortic root.

[0044]FIGS. 12A-12F illustrate various steps of another method of the
present invention for delivering a stent of the present invention using
an implantation system of the present invention.

[0045]FIGS. 13A-13C illustrate various exemplary mandrel designs for
fabricating the stents and stent grafts of the present invention.

[0046]FIG. 14 illustrates an exemplary wire winding pattern to form a
stent of the present invention.

[0047]FIG. 15 illustrates one manner of grafting a stent of the present
invention.

[0048]FIG. 16 illustrates a longitudinal cross-sectional view of the
distal end of another delivery and deployment system of the present
invention with an implantable device of the present invention shown
partially deployed from the implantation system.

[0049]FIG. 17 illustrates a perspective view of another delivering and
deploying system of the present invention.

[0050]FIGS. 18A and 18B are cross-sectional side views of a
deployment/attachment mechanism at a distal end of the system of FIG. 17
having a stent operably attached and deployed, respectively.

[0051]FIG. 19 is a cross-sectional side view of the handle portion of the
system of FIG. 17 in which a spring mechanism is employed to spring-load
the deployment/attachment mechanism of FIGS. 18A and 18B.

[0052]FIGS. 20A and 20B are cross-sectional side views of the handle of
the system of FIG. 17 and particularly illustrate the flushing features
of the system.

[0053]FIGS. 21A and 21B are side and top views, respectively, of the
distal end of a steerable side branch catheter of a delivery/deployment
system of the present invention operatively engaged with a side branch
lumen of a stent of the present invention.

[0054]FIG. 22 illustrates use of the steering ability of the side branch
catheter of FIGS. 21A and 21B.

[0055]FIG. 23 illustrates use of an optional filter wire with the side
branch catheter of FIG. 22.

[0056]FIGS. 24A and 24B are side and end views, respectively, of a sheath
of a delivery/deployment system of the present invention having
radiopaque markings.

[0057]FIG. 25 is another sheath of the present invention having walls
reinforced with a braid material

DETAILED DESCRIPTION OF THE INVENTION

[0058]Before the devices, systems and methods of the present invention are
described, it is to be understood that this invention is not limited to
particular therapeutic applications and implant sites described, as such
may vary. It is also to be understood that the terminology used herein is
for the purpose of describing particular embodiments only, and is not
intended to be limiting, since the scope of the present invention will be
limited only by the appended claims.

[0059]Unless defined otherwise, all technical and scientific terms used
herein have the same meaning as commonly understood by one of ordinary
skill in the art to which this invention belongs. The terms "proximal"
and "distal" when used to refer to the delivery and deployment systems of
the present invention are to be understood to indicate positions or
locations relative to the user where proximal refers to a position or
location closer to the user and distal refers to a position or location
farther away from the user. When used with reference to the implantable
devices of the present invention, these terms are to be understood to
indicate positions or locations relative to a delivery and deployment
system when the implantable devices is operatively positioned within the
system. As such, proximal refers to a position or location closer to the
proximal end of the delivery and deployment system and distal refers to a
position or location closer to the distal end of the delivery and
deployment system. The term "implant" or "implantable device" as used
herein includes but is not limited to a device comprising a stent, a
graft, a stent-graft or the like.

[0060]The present invention will now be described in greater detail by way
of the following description of exemplary embodiments and variations of
the devices, systems and methods of the present invention. The invention
generally includes an implantable device which includes a tubular member
in the form of a stent, a graft or a stent graft, where the device may
further include one or more branching or transverse tubular members
laterally extending from the main or primary tubular member. The
invention further includes a system for the percutaneous, endovascular
delivery and deployment of the implantable device at a target implant
site within the body. The implant site may be any tubular or hollow
tissue lumen or organ; however, the most typical implant sites are
vascular structures, particularly the aorta. A feature of the invention
is that it addresses applications involving two or more intersecting
tubular structures and, as such, is particularly suitable in the context
of treating vascular trees such as the aortic arch and the infrarenal
aorta.

Implantable Devices of the Present Invention

[0061]Referring now to the figures and to FIGS. 1A and 1B in particular,
there are illustrated exemplary embodiments of implantable devices of the
present invention. Each of the devices has a primary or main tubular
member and at least one laterally extending tubular branch, however, the
implantable devices of the present invention need not have side branches.

[0062]FIG. 1A illustrates one variation of an implantable device 2 having
a primary tubular portion, body or member 4 and laterally extending side
branches 6a, 6b and 6c, interconnected and in fluid communication with
main body 4 by way of lateral openings within the body. The proximal and
distal ends of the main tubular member 4 terminate in crowns or apexes 8,
the number of which may vary. The distal ends of the side branches 6a, 6b
and 6c terminate in crowns or apexes 10a, 10b and 10c, respectively, the
number of which may also vary. Device 2 is particularly configured for
implantation in the aortic arch where primary tubular member 4 is
positionable within the arch walls and tubular branches 6a, 6b and 6c are
positionable within the innominate artery, the left common carotid artery
and the left subclavian artery, respectively.

[0063]As will be described in greater detail below, the deployment or
attachment members of the subject delivery and deployment systems, are
looped through the apexes 10a, 10b and 10c, or through eyelets (not
shown) extending from the distal ends of the apexes of the device 2. The
attachment members of the present invention may be any elongated member
including but not limited to strings, filaments, fibers, wires, stranded
cables, tubings or other elongated member which are releasably attachable
to the distal ends of the various lumens of the stent. Means of
releasable attachment include but are not limited to electrolytic
erosion, thermal energy, magnetic means, chemical means, mechanical means
or any other controllable detachment means.

[0064]FIG. 1B illustrates another variation of a device 12 having a
primary tubular portion or member 14 and laterally extending branches 16a
and 16b, interconnected and in fluid communication with main body 14 by
way of lateral openings within the body. The proximal and distal ends of
the main tubular member 14 terminate in crowns or apexes 18 which are
employed as described above with respect to FIG. 1A while the distal ends
of the side branches 16a and 16b terminate in crowns or apexes 18a and
18b, respectively. Device 12 is particularly configured for implantation
in the infra-renal aorta where primary tubular member 14 is positionable
within the walls of the aorta and tubular branches 16a and 16b are
positioned within the right and left renal arteries, respectively.

[0065]Those skilled in the art will recognize that the subject implants
may have any number and configuration of lumens (e.g., a single main
lumen without side branch lumens, a main lumen and one or more side
branch lumens) where the one or more side branch lumens may be positioned
at any appropriate location along the length of the main lumen and at any
angle with respect to the longitudinal axis of the main lumen, and where
the there are two or more side branch lumens, the lumens may be spaced
axially and circumferentially angled relative to each other to
accommodate the target vasculature into which the implant is to be
placed. Additionally, the length, diameter and shape (e.g., radius of
curvature) of each of the implant's lumens may vary as needed to
accommodate the vessel into which it is positioned. In certain
applications, particularly where treating a vascular aneurysm having a
relatively large neck section located near a juncture between the main
vessel and a tributary vessel, it may be preferential to provide a
branched stent where the side branch lumens are relatively longer than
average. The lengthier stent branches can bridge the neck opening while
maintaining sufficient length at their distal ends to extend a distance
into a vascular side branch sufficient to anchor the stent.

[0066]Typically, the subject devices for most vascular applications will
have a main branch lumen having an unconstrained length in the range from
about 1 cm to about 25 cm and an unconstrained diameter in the range from
about 2 mm to about 42 mm; and side branch lumens having an unconstrained
length in the range from about 0.5 cm to about 8 cm and an unconstrained
diameter in the range from about 2 mm to about 14 mm. For aortic
applications, the unconstrained length of the main lumen is typically
from about 8 cm to about 25 cm and the unconstrained diameter is in the
range from about 15 mm to about 42 mm; and the side branch lumens will
have an unconstrained length in the range from about 2 cm to about 8 cm
and an unconstrained diameter in the range from about 5 mm to about 14
mm. Where the dimension is the diameter of the main lumen of the stent,
the reduced diameter is more likely to be closer to one tenth of the
unreduced diameter. For renal applications, the main branch lumen will
have an unconstrained length in the range from about 2 cm to about 20 cm
and an unconstrained diameter in the range from about 12 mm to about 25
mm; and the side branch lumens will have an unconstrained length in the
range from about 0.5 cm to about 5 cm and an unconstrained diameter in
the range from about 4 mm to about 12 mm. For coronary applications, the
main branch lumen will have an unconstrained length in the range from
about 1 cm to about 3 cm and an unconstrained diameter from about 2 mm to
about 5 mm; and the side branch lumens will have an unconstrained length
in the range from about 0.5 cm to about 3 cm and an unconstrained
diameter in the range from about 2 mm to about 5 mm. For applications in
smaller vessels, such as the neurovasculature, these dimensions will of
course be smaller. In certain applications, particularly where treating a
vascular aneurysm having a relatively large neck section located near a
juncture between the main vessel and a tributary vessel, it may be
preferential to provide a branched stent where the side branch lumens are
relatively longer than average. The lengthier stent branches can bridge
the neck opening while maintaining sufficient length at their distal ends
to extend a distance into a vascular side branch sufficient to anchor the
stent.

[0067]It is also contemplated that therapeutic or diagnostic components or
devices may be integrated with the subject implants. Such devices may
include but are not limited to prosthetic valves, such as cardiac valves
(e.g., an aortic or pulmonary valve) and venous valves, sensors to
measure flow, pressure, oxygen concentration, glucose concentration,
etc., electrical pacing leads, etc. For example, as illustrated in FIG.
1E, an implant 210 for treating the aortic root is provide which includes
a mechanical or biological prosthetic valve 216 employed at a distal end
of the main lumen 212. Device 210 further includes two smaller, generally
opposing side branch lumens 214a and 214b adjustably aligned for
placement within the right and left coronary ostia, respectively. The
length of the stent graft may be selected to extend to a selected
distance where it terminates at any location prior to, within or
subsequent to the aortic arch, e.g., it may extend into the descending
aorta. Any number of additional side branches may be provided for
accommodating the aortic arch branch vessels.

[0068]Those skilled in the art will appreciate that any suitable stent or
graft configuration may be provided to treat other applications at other
vascular locations at or near the intersection of tvo or more vessels
(e.g., bifurcated, trifurcated, quadrificated, etc.) including, but not
limited to, the aorto-illiac junction, the femoral-popiteal junction, the
brachyceplialic arteries, the posterior spinal arteries, coronary
bifurcations, the carotid arteries, the superior and inferior mesenteric
arteries, general bowel and stomach arteries, cranial arteries and
neurovascular bifurcations.

[0069]The stents and grafts of the present invention may be made of any
suitable materials known in the art. Preferably, the stent is constructed
of wire, although any suitable material may be substituted. The wire
stent should be elastically compliant, for example, the stent may be made
of stainless steel, elgiloy, tungsten, platinum or nitinol but any other
suitable materials may be used instead of or in addition to these
commonly used materials.

[0070]The stents may have any suitable wire form pattern or may be cut
from a tube or flat sheet. In one embodiment, the entire stent structure
is fabricated from a single wire woven into a pattern of interconnected
cells forming, for example, a closed chain link configuration. The
structure may have a straight cylindrical configuration, a curved tubular
configuration, a tapered hollow configuration, have asymmetrical cell
sizes, e.g., cell size may vary along the length or about the
circumference of the stent. In certain stent embodiments, the cell size
of the side branches lumens is gradually reduced in the distal direction.
This further facilitates the ability to selectively stretch the
distalmost portion of the side branch lumens and, thus, making it easier
for a physician to guide the distal end of the side branch into a
designated vessel. The ends of the main stent lumen and/or the end of one
or more side branch stent lumens may be flared. The struts of the stent
(i.e., the elemental portions that form a cell) may vary in diameter (in
wire embodiments) or thickness or width (in sheet and cut tube
embodiments).

[0071]In one particular embodiment, the stent is configured from a
single-wire. The single-wire stent configuration is advantageous in that
through selective interlacing of the connection points along the length
of the stent, it provides for adjustability in the angular orientation of
the side branch stents relative to each other and relative to the main
stent lumen within a selected range that can accommodate any possible
variation in the anatomy being treated. Such angular orientation of the
side branch lumens may be axial, circumferential or both.

[0072]FIG. 1c illustrates an implant device 20 in which side branch lumens
24 and 26 each has an angular orientation, defined by angle α, with
respect to main lumen 22, and have an angular orientation, defined by
angle β, with respect to each other. FIG. 1D is an end view of
implant device 20 which illustrates the circumferential orientation,
defined by angle θ, between side branch lumens 22 and 24. Typical
ranges of the various angles are as follows: from about 10° to
about 170° for angle α, from 0° to about 170°
for angle β, and from 0° to 360° for angle θ.
These orientations may be provided by the fabrication process resulting
in a stent which has naturally biased orientations in an unconstrained,
pre-deployed condition, i.e., the neutral state. One or more of these
orientations may be selectively adjusted within the angle ranges provided
above upon delivery and placement of the branch lumens within the
respective vessel lumens. This design also allows for adjustability in
the linear spacing between the side branch stents by stretching and/or
foreshortening of the main lumen of the stent. Further, the side branch
portions can be elongated to allow for placement of an oversized stent in
a smaller branch vessel thereby providing adequate apposition between the
stent and the vessel wall. It should be noted that the adjustability of
the stent does not compromise the radial force needed to fixate or anchor
and prevent migration and endoleak of the device.

[0073]The subject devices may also be fabricated such that their lumens
may have constant or variable stiffness/flexibility along their lengths
as well as about their circumferences. Greater flexibility can better
accommodate curvaceous vasculature encountered during delivery and at the
implant site. Such a feature is highly beneficial in aortic arch stenting
applications due to the relatively "tight" curve of the arch. Enhanced
stiffness, on the other hand, particularly at the end portions of a
lumen, imparts a greater radial force thereby resisting migration of the
device within the vasculature after placement. Variable
flexibility/stiffness may be implemented in a variety of ways.

[0074]The gauge or thickness of the strut or struts (i.e., the elemental
portions that form a stent cell) used to fabricate the devices may vary
where thicker gauges impart greater stiffness and thinner gauges impart
greater flexibility. The struts of a stent may vary in diameter (in wire
embodiments) or thickness or width (in sheet and cut tube embodiments).
In one variation, a single wire or filament may be used where the gauge
selectively varies along its length. The thicker gauge portions are used
to form at least the end portions of the stent lumen(s) to increase their
radial force thereby reducing the risk of stent migration. Conversely,
the narrower gauge portion(s) of the wire form at least a central portion
of the main stent lumen (and portions of the side branch lumens) which
may be relatively more flexible than the end portions to facilitate
delivery of the stent within tortuous or curving vasculature or enabling
the device to be compact into the delivery sheath more easily. For aortic
stenting applications, this may be accomplished by a wire having one to
two centimeter portions at each of its ends having a larger diameter than
the remaining central portion. Another example of selectively reducing
the wire cross sectional diameter is to make the struts of the side
branch stents smaller in diameter.

[0075]In other embodiments, more than one wire is used where the wires
each have constant gauges along their respective lengths but differ from
wire to wire. Larger gauge wire(s) may be used to form the stent ends or
other areas where increased stiffness is required while narrower gauge
wire(s) may be used to form other portions, e.g., the central portions of
the stent lumens, where increased flexibility is required. Additionally
or alternatively, the larger gauge wire can be selectively doubled-over
or wrapped with the narrow gauge wire at selected points or locations
about the stent to bolster the stiffness at those particular sites.

[0076]In one variation, two or more wires may be employed to form the
device whereby the wire ends, i.e., four wire ends in the case of a
device made from two wires, are joined together. The location(s) about
the lumen s at which the wires cross-each and/or at which their ends are
joined about is/are selected to minimize stiffness in certain areas along
or about the lumen and/or to enhance stiffness in one or more other areas
of the device, i.e., to provide relative stiffness and flexibility
between portions of the stent. For example, in aortic arch applications,
the portion of the main lumen of the stent intended to be aligned along
the inferior wall of the arch is preferentially relatively more flexible
and/or less stiff than the portion of the stent intended to be aligned
along the superior wall of the arch, as the inferior wall has a tighter
radius of curvature. Accordingly, it may be desirable to minimize the
joinder and/or intersection points of the wires along this portion of the
stent.

[0077]It may also be desirable to provide greater stiffness at the
juncture between the main lumen and side branch lumens. Aortic aneurysms,
and particularly aneurysms located at the intersection of the aortic arch
and one or more of its tributary vessels, can result in relatively large
volumes of not-so-defined perimeters, i.e., "sacks", within the
vasculature. Without a vessel wall against which to buttress itself, a
stent juncture may be more susceptible to kinking. Stiffening the stent's
juncture points can prevent such kinking.

[0078]Co-pending U.S. patent application Ser. No. 11/539,478 filed Oct. 6,
2006 and another U.S. Patent Application (having Attorney Docket No.
DUKEPZ01101) filed contemporaneously herewith, both entitled Vascular
Implants and Methods of Fabricating the Same and incorporated herein by
reference, disclose stent devices having many of the features for
selectively enhancing the stiffness and flexibility properties described
above.

[0079]As mentioned above, the implantable devices of the present invention
may include a stent or a graft or a combination of the two, referred to
as a stent graft, a stented graft or a grafted stent. The graft portion
of a stent graft may be made from a textile, polymer, latex, silicone
latex, polyetraflouroethylene, polyethylene, Dacron polyesters,
polyurethane or other or suitable material such as biological tissue. The
graft material must be flexible and durable in order to withstand the
effects of installation and usage. One of skill in the art would realize
that grafts of the subject invention may be formulated by many different
well known methods such as for example, by weaving or formed by dipping a
substrate in the desired material. Exemplary graft fabrication methods
are disclosed in the contemporaneously filed U.S. patent application
referenced above.

[0080]Biological tissues that may be used to form the graft material (as
well as the stent) include, but are not limited to, extracellular
matrices (ECMs), acellularized uterine wall, decellularized sinus cavity
liner or membrane, acellular ureture membrane, umbilical cord tissue,
decelluarized pericardium and collagen. Suitable ECM materials are
derived from mammalian hosts sources and include but are not limited to
small intestine submucosa, liver basement membrane, urinary bladder
submucosa, stomach submucosa, the dermis, etc. Extracellular matrices
suitable for use with the present invention include mammalian small
intestine submucosa (SIS), stomach submucosa, urinary bladder submucosa
(UBS), dermis, or liver basement membranes derived from sheep, bovine,
porcine or any suitable mammal.

[0081]Submucosal tissues (ECMs) of warm-blooded vertebrates are useful in
tissue grafting materials. Submucosal tissue graft compositions derived
from small intestine have been described in U.S. Pat. No. 4,902,508
(hereinafter the '508 patent) and U.S. Pat. No. 4,956,178 (hereinafter
the '178 patent), and submucosal tissue graft compositions derived from
urinary bladder have been described in U.S. Pat. No. 5,554,389
(hereinafter the '389 patent). All of these (ECMs) compositions are
generally comprised of the same tissue layers and are prepared by the
same method, the difference being that the starting material is small
intestine on the one hand and urinary bladder on the other. The procedure
detailed in the '508 patent, incorporated by reference in the '389 patent
and the procedure detailed in the '178 patent, includes mechanical
abrading steps to remove the inner layers of the tissue, including at
least the lumenal portion of the tunica mucosa of the intestine or
bladder, i.e., the lamina epithelialis mucosa (epithelium) and lamina
propria, as detailed in the '178 patent. Abrasion, peeling, or scraping
the mucosa delaminates the epithelial cells and their associated basement
membrane, and most of the lamina propria, at least to the level of a
layer of organized dense connective tissue, the stratum compactum. Thus,
the tissue graft material (ECMs) previously recognized as soft tissue
replacement material is devoid of epithelial basement membrane and
consists of the submucosa and stratum compactum.

[0082]Examples of a typical epithelium having a basement membrane include,
but are not limited to the following: the epithelium of the skin,
intestine, urinary bladder, esophagus, stomach, cornea, and liver. The
epithelial basement membrane may be in the form of a thin sheet of
extracellular material contiguous with the basilar aspect of epitielial
cells. Sheets of aggregated epithelial cells of similar type form an
epithelium. Epithelial cells and their associated epithelial basement
membrane may be positioned on the lumenal portion of the tunica mucosa
and constitute the internal surface of tubular and hollow organs and
tissues of the body. Connective tissues and the submucosa, for example,
are positioned on the abluminal or deep side of the basement membrane.
Examples of connective tissues used to form the ECMs that are positioned
on the abluminal side of the epithelial basement membrane include the
submucosa of the intestine and urinary bladder (UBS), and the dermis and
subcutaneous tissues of the skin. The submucosa tissue may have a
thickness of about 80 micrometers, and consists primarily (greater than
98%) of a cellular, eosinophilic staining (H&E stain) extracellular
matrix material. Occasional blood vessels and spindle cells consistent
with fibrocytes may be scattered randomly throughout the tissue.
Typically the material is rinsed with saline and optionally stored in a
frozen hydrated state until used.

[0083]Fluidized UBS, for example, can be prepared in a manner similar to
the preparation of fluidized intestinal submucosa, as described in U.S.
Pat. No. 5,275,826 the disclosure of which is expressly incorporated
herein by reference. The UBS is comminuted by tearing, cutting, grinding,
shearing or the like. Grinding the UBS in a frozen or freeze-dried state
is preferred although good results can be obtained as well by subjecting
a suspension of submucosa pieces to treatment in a high speed (high
shear) blender and dewatering, if necessary, by centrifuging and
decanting excess water. Additionally, the comminuted fluidized tissue can
be solubilized by enzymatic digestion of the bladder submucosa with a
protease, such as trypsin or pepsin, or other appropriate enzymes for a
period of time sufficient to solubilize said tissue and form a
substantially homogeneous solution.

[0084]The coating for the stent may be powder forms of UBS. In one
embodiment a powder form of UBS is prepared by pulverizing urinary
bladder submucosa tissue under liquid nitrogen to produce particles
ranging in size from 0.1 to 1 mm2. The particulate composition is
then lyophilized overnight and sterilized to form a solid substantially
anhydrous particulate composite. Alternatively, a powder form of UBS can
be formed from fluidized UBS by drying the suspensions or solutions of
comminuted UBS.

[0085]Other examples of ECM material suitable for use with the present
invention include but are not limited to fibronectin, fibrin, fibrinogen,
collagen, including fibrillar and non-fibrillar collagen, adhesive
glycoproteins, proteoglycans, hyaluronan, secreted protein acidic and
rich in cysteine (SPARC), thrombospondins, tenacin, and cell adhesion
molecules, and matrix metalloproteinase inhibitors.

[0086]The stent may be processed in such a way as to adhere an ECM
covering (or other material) to only the wire, and not extend between
wire segments or within the stent cells. For instance, one could apply
energy in the form of a laser beam, current or heat to the wire stent
structure while the ECM has been put in contact with the underlying
structure. Just as when cooking meat on a hot pan leaves tissue, the ECM
could be applied to the stent in such a manner.

[0087]Subsequent to implant of the subject devices, the ECM portion of the
implant is eventually resorbed by the surrounding tissue, taking on the
cellular characteristics of the tissue, e.g., endothelium, smooth muscle,
adventicia, into which it has been resorbed. Still yet, an ECM
scaffolding having a selected configuration may be operatively attached
to a stent or stent graft of the present invention at a selected location
whereby the ECM material undergoes subsequent remodeling to native tissue
structures at the selected location. For example, the ECM scaffolding may
be positioned at the annulus of a previously removed natural aortic valve
configured in such a way as to create the structural characteristics of
aortic valve leaflets and whereby the implant provides valve function.

[0088]The subject stents, grafts and/or stent grafts may be coated in
order to provide for local delivery of a therapeutic or pharmaceutical
agent to the disease site. Local delivery requires smaller dosages of
therapeutic or pharmaceutical agent delivered to a concentrated area; in
contrast to systemic dosages which require multiple administrations and
loss of material before reaching the targeted disease site. Any
therapeutic material, composition or drug, may be used including but not
limited to, dexamethasone, tocopherol, dexamethasone phosphate, aspirin,
heparin, coumadin, urokinase, streptokinase and TPA, or any other
suitable thrombolytic substance to prevent thrombosis at the implant
site. Further therapeutic and pharmacological agents include but are not
limited to tannic acid mimicking dendrimers used as submucosa stabilizing
nanomordants to increase resistance to proteolytic degradation as a means
to prevent post-implantational aneurysm development in decellularized
natural vascular scaffolds, cell adhesion peptides, collagen mimetic
peptides, hepatocyte growth factor, proliverative/antimitotic agents,
paclitaxel, epidipodophyllotoxins, antibiotics, anthracyclines,
mitoxantrone, bleomycins, plicamycin, and mitomycin, enzymes,
antiplatelet agents, non-steroidal agents, heteroaryl acetic acids, gold
compounds, immunosuppressives, angiogenic agents, nitric oxide donors,
antisense oligonucleotides, cell cycle inhibitors, and protease
inhibitors.

[0089]For purposes of agent delivery, the subject stents, grafts and/or
stent grafts are coated with a primer layer onto a surface. The primer
layer formulates a reservoir for containing the
therapeutic/pharmaceutical agent. The overlapping region between the
primer layer and active ingredient may be modified to increase the
permeability of the primer layer to the active ingredient. For example,
by applying a common solvent, the active ingredient and the surface layer
mix together and the active ingredient gets absorbed into the primer
layer. In addition, the primer layer may also be treated to produce an
uneven or roughened surface. This rough area entraps the active
ingredient and enhances the diffusion rate of the ingredient when the
stent is inserted into the patient's body. As such, the implant has the
ability to diffuse drugs or other agents at a controllable rate.
Furthermore, one of skill in the art would understand that the subject
invention may provide a combination of multiple coatings, such as the
primer layer may be divided into multiple regions, each containing a
different active ingredient.

[0090]The subject implants may also be seeded with cells of any type
including stem cells, to promote angiogenesis between the implant and the
arterial walls. Methods have included applying a porous coating to the
device which allows tissue growth into the interstices of the implant
surface. Other efforts at improving host tissue in growth capability and
adhesion of the implant to the host tissue have involved including an
electrically charged or ionic material in the tissue-contacting surface
of the device.

[0091]The stent, graft, or stent graft of the present invention may also
include a sensor or sensors to monitor pressure, flow, velocity,
turbidity, and other physiological parameters as well as the
concentration of a chemical species such as for example, glucose levels,
pH, sugar, blood oxygen, glucose, moisture, radiation, chemical, ionic,
enzymatic, and oxygen. The sensor should be designed to minimize the risk
of thrombosis and embolization. Therefore, slowing or stoppage of blood
flow at any point within the lumen must be minimized. The sensor may be
directly attached to the outer surface or may be included within a packet
or secured within the material of the stent, graft, or stent graft of the
present invention. The biosensor may further employ a wireless means to
deliver information from the implantation site to an instrument external
to the body.

[0092]The stent, graft or stent graft may be made of visualization
materials or be configured to include marking elements, which provide an
indication of the orientation of the device to facilitate proper
alignment of the stent at the implant site. Any suitable material capable
of imparting radio-opacity may be used, including, but not limited to,
barium sulfate, bismuth trioxide, iodine, iodide, titanium oxide,
zirconium oxide, metals such as gold, platinum, silver, tantalum,
niobium, stainless steel, and combinations thereof. The entire stent or
any portion thereof may be made of or marked with a radiopaque material,
i.e., the crowns of the stent.

Device Fabrication Methods

[0093]The stent of the present invention may be fabricated in many ways.
One method of making the stent is by use of a mandrel device such as the
mandrel devices 320, 330 and 340 illustrated in FIGS. 13A-13C,
respectively. Each of the devices has at least a main mandrel component
322, 332 and 342, respectively, with a plurality of selectively
positioned pinholes 324, 334 and 344, respectively, within which a
plurality of pins (not shown) are selectively positioned, or from which a
plurality of pins is caused to extend. As is described in more detail
below, the stent structure is formed by selectively wrapping a wire
around the pins. Where the stent is to have one or more side branch
lumens, the mandrel device, such as device 340, may be provided with at
least one side mandrel 346 extending substantially transverse to the main
mandrel 342, where the number of side mandrels preferably corresponds to
the number of stent side branches to be formed. The mandrel devices may
be modular where side branch mandrels of varying diameters and lengths
can be detachably assembled to the main mandrel. The configuration of the
main mandrel as well as the side branch mandrel(s) may have any suitable
shape, size, length, diameter, etc. to form the desired stent
configuration. Commonly, the mandrel components have a straight
cylindrical configuration (see FIGS. 13A and 13C) having a uniform
cross-section, but may be conical with varying diameters along a length
dimension (see FIG. 13B), frustum conical, have an oval cross-section, a
curved shape, etc.

[0094]The pins may be retractable within the mandrel components or are
themselves removable from and selectively positionable within holes
formed in the mandrel components. Still yet, the mandrel device may be
configured to selectively extend and retract the pins. The number of pins
and the distance and spacing between them may be varied to provide a
customized pin configuration. This customization enables the fabrication
of stents having varying sizes, lengths, cell sizes, etc. using a limited
number of mandrel components. For example, in one variation, the pins are
arranged about the mandrel components in an alternating pattern such as
for example, where four out of eight pin holes per row will be filled
with pins. Alternatively, a selection of mandrels may be provided, each
having a unique pinhole pattern which in turn defines a unique stent cell
pattern.

[0095]To form the stent, a shape memory wire, such as a NITINOL wire,
having a selected length and diameter are provided. Typically, the length
of the wire ranges from about 9 to about 12 feet long, but may be longer
if needed or shorter if more practical. The Wire's diameter is typically
in the range from about 0.001 to about 0.020 inch. After providing a
mandrel device having winding pins at the desired points or locations on
the mandrel components, the wire is wound about the pins in a selected
direction and in a selected over-and-under lapping pattern, e.g., a
zigzag pattern, to form a series of interconnected undulated rings
resulting in a desired cell pattern.

[0096]An exemplary wire winding pattern 350 is illustrated in FIG. 14.
Starting from one end of the main mandrel, the wire 352 is wound around
the pins 354 in a zigzag pattern back and forth from one end of the main
mandrel to the other until the cells of the main lumen of the stent have
been formed. Next, the same wire, still attached to the mandrel device,
is used to form the side branch lumen(s) where the wire is wrapped in a
zigzag fashion from the base of the side branch mandrel to the distally
extending end and back again until all of the cells of the side branch
have been created. Then the wire is wound about the main mandrel along a
path that is at an angle to longitudinal axis of the main mandrel where
the wire is doubled over itself along certain cell segments 356. It
should be noted that any lumen of the stent may be fabricated first,
followed by the others, or the winding pattern may be such that portions
of the various lumens are formed intermittently.

[0097]The mandrel device with the formed wire stent pattern are then
heated to a temperature in the range from about 480° C. to about
520° C. and typically to about 490° C. for approximately 20
minutes, however, this time may be reduced by using a salt bath. The
duration of the heat-setting step is dependent upon the time necessary to
shift the wire material from a Martensitic to an Austenitic phase. The
assembly is then air cooled or placed into a water bath to quench for 30
seconds or more and then allowed to air dry. Once the stent is
sufficiently dried, the pins are either pulled from the mandrel device or
retracted into the hollow center of the mandrel by an actuation of an
inner piece which projects the pins out their respective holes in the
outer surface of the mandrel. The stent with its interconnected lumens
can then be removed from the mandrel device. Alternatively, with the
mandrel components detached from one another, one of the lumens, e.g.,
the main stent lumen, may be formed first followed by formation of a side
branch lumen after attachment of a side mandrel to the main mandrel.

[0098]Optionally, selected regions of the main body or the portions of the
wire forming the side branch lumen cells may be selectively reduced in
diameter by etching or e-polishing so as to exert less radial force than
that wire portion of the stent that has not been reduced in wire
diameter. One example of a selective reduction of wire diameter in the
main body of the stent is to leave a one to two centimeter
circumferential portion on each of the proximal and distal ends to allow
high radial force at those regions to secure the stent from migration
while the center portion between those high radial force regions can be
reduced in cross sectional wire diameter in order to facilitate
stretching the stent more easily during placement or allowing it to
compact into the delivery sheath more easily over a long length. Another
example of selectively reducing the wire cross sectional diameter is to
make the struts of the side branch smaller in diameter. This can be done
by selective immersion of the side branch in an acid during manufacture
to reduce the amount of metal in a particular region of the stent.
Another method to accomplish the desired result of preferentially
reducing side branch longitudinal stiffness and/or outward radial force
of the side branch component is to use an electropolishing apparatus. By
placing the woven solid wire stent into an electrolyte bath and applying
a voltage potential across an anode-cathode gap, where the stent itself
is the anode, metal ions are dissolved into the electrolytic solution.
Alternatively, or subsequently, the process may be reversed wherein the
stent becomes the cathode and the side branch or other selected region of
the stent may be electroplated with a similar or different metal in ionic
solution, for instance gold or platinum, in order to either change the
mechanical properties or to enhance the radiopacity of the selected
region. Those skilled in the art of electroplating and electropolishing
will recognize that there are techniques using a "strike" layer of a
similar material to the substrate in order to enhance the bonding of a
dissimilar material to the substrate. An example would be the use of a
pure nickel strike layer on top of a nickel titanium (NITINOL) substrate
in order to subsequently bond a gold or platinum coating to the
substrate.

[0099]Another method of making the stent is to cut a thin-walled tubular
member, such as stainless steel tubing, to remove portions of the tubing
in the desired pattern for the stent, leaving relatively untouched the
portions of the metallic tubing which are to form the stent. The stent
also can be made from other metal alloys such as tantalum,
nickel-titanium, cobalt-chromium, titanium, shape memory and superelastic
alloys, and the nobel metals such as gold or platinum.

[0100]In accordance with the invention, one of skill in the art would know
that several different methods may be employed to make the subject stents
such as using different types of lasers; chemical etching; electric
discharge machining; laser cutting a flat sheet and rolling it into a
cylinder; all of which are well known in the art at this time.

[0101]Where a stent graft 360 is to be formed by the addition of a graft
material 362, such as an ECM, to the subject stent 364, any manner of
attaching the graft material to the wire form may be used. In one
variation, the graft material is attached by way of a suture 366. As
such, one edge 370 of the graft material is stitched lengthwise to the
stent frame along the stents length, where at least one knot 368 is tied
at each apex of the stent to secure an end of the graft to the stent.
Then the graft material is stretch around the surface of the stent and
the opposite edge 372 of the graft is overlapped with the already
attached edge 370 and independently stitched to the stent frame to
provide a leak free surface against which blood cannot escape. The graft
material is stretched to an extent to match the compliance of the stent
so that it does not drape when the stent is in the expanded state. Upon
complete attachment of the graft material to the stent, the graft is
dehydrated so that it snuggly shrinks onto the stent frame similar to
heat shrink tubing would when heated.

Delivery and Deployment Systems of the Present Invention

[0102]Referring now to FIGS. 2A and 2B, there is shown a system 30 of the
present invention for implanting the devices of the present invention.
System 30 includes a distal catheter portion 32 and a proximal or handle
portion 34. Catheter portion 32 is configured for positioning within the
vasculature or other pathway leading to the implant site, and includes
various elongated members having a plurality of lumens, many of them
multi-functional, for guide wire, pull-wire, and fluid passage from one
end of the device to the other. Catheter portion 32 includes a
translatable outer sheath 38 having a lumen within which an intermediate
member 40 is received. The proximal end of outer sheath 38 is configured
with a fitting 50 for coupling to a distal hub 52 of intermediate portion
40. Fitting 50 is configured with an internal valve mechanism which
fluidly seals the luminal space between the walls of outer member 38 and
intermediate member 40, thereby preventing leakage of blood therefrom.
Fitting 50 may further include a flush port (not shown) for evacuation of
any residual air as is common in catheter preparation. An inner member 42
is received and translatable within a lumen 138 (see FIG. 6A) of
intermediate member 40 and defines a main body guide wire lumen 44 for
translation of a guide wire 48 therethrough. Inner member 42 terminates
at a conical distal tip 46 which facilitates forward translation of the
device through tortuous vasculature. The outer member, intermediate
member and inner member tubings (as well as any catheter components
discussed below) may be made from materials used to construct
conventional intravascular sheaths and catheters, including but not
limited to biocompatible plastics reinforced with braided materials or
any other biocompatible materials which are substantially flexible.

[0103]The proximal portion 34 of delivery and deployment system 30
includes proximal and distal handle portions 36a, 36b which translate
axially with respect to each other. Inner member 42 is fixed to proximal
portion 36a of the handle and intermediate member 40 is fixed to distal
portion 36b of the handle such that axial separation and extension of the
two handle portions relative to each other controls the amount of
extension and foreshortening undergone by a stent operatively loaded
within the delivery system, as will be explained in greater detail below.

[0104]As mentioned above, in one variation of the present invention,
delivery and deployment of an implant is accomplished by the use of a
plurality of designated attachment lines, strings, wires or filaments.
More particularly, a single string or a set or plurality of strings is
provided for controlling and releasably attaching each free end of the
implant to the delivery system. Two separate strings or sets of strings
are employed to control the main tubular portion of an implantable
device-one string or set of strings for controlling the distal end and
the other for controlling the proximal end of the device. For each
lateral branch of the implant, an additional string or set of strings is
provided. The number of strings in each set correlates to the number of
crowns or connecting points provided at the respective ends (i.e., at the
proximal and distal ends of the main stent portion and at the distal ends
of the branch portions) of the device. Each string is interlooped with a
designated crown with both of its ends positioned and controlled at the
handle of the device, where one end of each attachment string is
permanently affixed to the delivery and deployment system 30 and the
other end is releasably attachable to the delivery and deployment system
30. When operatively loaded within system 30, the luminal ends of the
implant are releasably attached to various portions of system 30. For
example, the distal end of the main lumen of the stent is releasably
attached to inner member 42, the proximal end of the main lumen of the
stent is releasably attached to intermediate member 40, and the distal
end of each side branch stent is releasably attached to a designated side
branch catheter 150 (see FIG. 6A).

[0105]FIGS. 21A and 21B illustrate one arrangement by which a side branch
catheter 460 carries, steers and deploys a stent side branch lumen 468. A
single deployment string 470 originating from a string lumen 464a within
catheter 460 is threaded or woven throughout the apices 474 of side
branch stent 468 and exited through another string lumen 464b within
catheter 460, where both ends of string 470 are retained a proximal end
of the deployment system as discussed above. Control and steerability of
side branch catheter 460 is accomplished in part by use of side branch
guidewire 466, as shown in FIG. 22, passed through the catheter's
guidewire lumen 462. The manner in which string 470 and the holds and
secures the distal end of side branch stent 468 to the outside of
catheter 460 also provides control and steerability. As best illustrated
in FIG. 22, the resulting tension placed on the distal end of catheter
460 by the side branch 468 enables controlled movement and directionality
of the catheter. For example, translational movement of catheter 460
along in an axial direction 477 results in the back and forth movement,
i.e., motion parallel to or in the same plane with the main stent lumen
462, of the distal end of the catheter, as indicated by arrows 475a,
475b. Conversely, rotational movement or torquing 480 of catheter body
460 results in side-to-side movement, i.e., motion lateral to or in a
plane perpendicular to the axis of the main stent lumen 472, i.e., of the
distal end of the catheter.

[0106]Each attachment string or set of attachment strings is controlled,
i.e., able to be fixed, released, tensioned, pulled, tightened, etc., by
a designated control mechanism. Accordingly, the number of control
mechanisms provided on the illustrated embodiment of the subject system
corresponds to the number of attachment string sets; however, control of
the string sets may be consolidated into a fewer number of control
mechanisms. The various control mechanisms may have any suitable
configuration and be mounted at any suitable location on system 30 where
one exemplary configuration and location of the control mechanisms is
illustrated in FIG. 2A. In particular, each control mechanism includes a
pair of controls in the form of knobs, dials, switches or buttons, for
example, where one control is for linearly translating, i.e., pulling,
the strings by their fixed ends through the deployment system 30 when
deploying the implant, and the other control is for selectively releasing
and fixing the free ends of the strings prior to deployment of the
implant.

[0107]Controls 70a, 70b and 72a, 72b, for controlling the distal and
proximal luminal ends, respectively, of the implant, are provided on
handle portions 36a and 36b, respectively. An additional pair of controls
for each set of attachment strings associated with each of the implant's
side or lateral branch lumens is provided on a hub releasably mounted to
intermediate member 40 where the collective hubs are serially arranged
between the proximal end 50 of outer sheath 38 and the distal end of
distal handle portion 36b. For example, for use with implant 2 of FIG. 1A
having three branch lumens 6a, 6b and 6c, three hubs 74, 76 and 78 and
associated pairs of controls, respectively, are provided where the most
distal pair of controls 74a, 74b controls the attachment strings for the
most distal of the stent branch lumens 6a, the second or middle pair of
controls 76a, 76b controls the attachment strings for the middle stent
branch lumen 6b, and the most proximal pair of controls 78a, 78b controls
the attachment strings for the most proximal of the stent branch lumens
6c.

[0108]Each pair of controls includes a fixed-end member 70a, 72a, 74a, 76a
and 78a, here in the form of a knob, to which one set, the fixed set, of
ends of the attachment strings is permanently anchored but which itself
is removable from the respective handle portion or hub in order to
manually pull the strings therethrough. This control maintains a constant
tension on the attachment strings and keeping the implant restrained
within the delivery system while the delivery system is being articulated
through the vasculature. As best illustrated in FIG. 2B, each knob is
positioned within a hemostatic valve 80 for preventing the back flow of
fluid, e.g., blood, out of the handle or hub before and after the knob is
removed therefrom. Each pair of controls also includes a releasable end
member or clamp 70b, 72b, 74b, 76b and 78b, here in the form of a dial or
drive screw, by which the free ends of the string set are releasably
anchored to the respective handle portion or hub. When ready to deploy a
respective luminal end of the implant, the drive screw is selectively
loosened to allow for release of the tension on the respective string
set. Those skilled in the art will appreciate that the relative
positioning and arrangement of the various control mechanisms may vary
with the intent of providing an organized, ergonomically designed
profile.

[0109]Referring now to FIGS. 2B, 3A and 3B, each side branch control hub
74, 76 and 78 is associated with a distally positioned side branch
catheter hub 84, 86 and 88, respectively (only the most proximally
positioned hubs 78 and 88 are illustrated in FIG. 2B). Extending between
each pair of hubs is a proximal portion 94a, 94b, 94c of side branch
catheters 150a, 150b, 150c, respectively (see FIG. 6A), which extends
from a sealable port 110a, 110b, 110c (see FIG. 2B) at the back end of
each control hub 74, 76 and 78 to a distal end and through respective
side branch catheter lumens 148 within intermediate member 40 (see FIG.
6A). Within each side branch catheter 150a, 150b, 150c is a side branch
guide wire lumen 152a, 152b, 152c (see FIG. 6A). Port 110a, 110b, 110c
allows for the entry and passage of a side branch guide wire 154a, 154b,
154c (see FIG. 6A) through a respective side branch guide wire lumen 152.
One or both of the side branch catheter and side branch guidewire may be
deflectable. Each of the control hubs 74, 76 and 78 are slidably engaged
with intermediate member 40. The undersides of the control hubs have cuff
96, a partial ring configuration or the like, such that hubs are filly
releasable from intermediate member 40 as well as slidable thereon. As
mentioned above, each of the side branch stent lumens is releasably
coupled to the distal end of side branch catheter 150a, 150b, 150c by way
of a designated attachment string or set of attachment strings.
Regardless of the relative position between the side branch control hubs
74, 76, 78 and the associated side branch catheter hubs 84, 86, 88, the
attachment string sets are held in complete tension in both
configurations illustrated in FIGS. 3A and 3B until they are released by
their respective control knobs 74b, 76b, and 78b. When the control hubs
are in a distal or close position relative to the catheter hubs, as
illustrated in FIGS. 2A and 3B, where the proximal portion 94a, 94b, 94c
of side branch catheter 150a, 150b, 150c is fully received within the
associated catheter hub, the side branch stents are held in a partially
deployed state. In the partially deployed state, the side branch stents
are held stretched, with tension being applied by the distal end of the
respective extended side branch catheter 94a, 94b, 94c removably attached
to the distal end of the stretched side branch stent apices or connection
points by the side branch catheters' respective string or string set. The
tension being applied to the distal end of each side branch stent is
transferred through the side branch stent thereby elongating its length
while simultaneously reducing the diameter. This allows for the
positioning of a larger stent diameter within a smaller diameter side
branch vessel. This partially deployed state, i.e., where the side branch
stent diameter is smaller than the side branch vessel into which it is
being placed, also allows for the flow of blood around the implant as
well as through it thereby allowing perfusion of downstream vessels and
organs during placement. It is preferential to have blood continue to
flow through intersecting side branch vessels during the procedure in
order to avoid ischemia to the effected downstream organs. The side
branch stent is stretched by the extension of the side branch catheter
which is releasably attached to the crowns of the distal end of the side
branch stent. The stretching of the side branch stent enables its
subsequent placement within an undersized, targeted side branch vessel.
Typically, the diameter of a side branch stent in its natural,
unconstrained state is about 5% to about 50% greater than the diameter of
the side branch vessel into which it is to be placed. Conversely, when
the control hubs are in a proximal or retracted position, as illustrated
in FIGS. 2B and 3A, each side branch stent is held in a deployed or
unstretched condition.

[0110]The side branch catheters 150a, 150b, 150c slidably extend at their
proximal ends 94a, 94b, 94c through respective side branch catheter hubs
84, 86, 88 and a hemostatic valve 92a, 92b, 92c positioned at the back
end of the catheter hub. Each side branch control hub 74, 76, 78 has a
luer fitting 110a, 110b, 110c (where only 110c is shown) which allows a
hemostatic valve (not shown) to be applied. The hemostatic valve may be a
Y arm adapter or a Toughy-Borst adapter which allows the sealed
introduction of a guidewire. The Y arm luer fitting allows for clearing
the guidewire lumen of air by flushing the catheter with saline prior to
inserting the catheter into the body. At subsequent stages of the
procedure, this lumen may be used to introduce radiographic dye in order
to visualize blood flow through the side branch arteries.

[0111]A main body port 76, as illustrated in FIG. 4, located on the back
end of proximal handle portion 36a is in fluid communication with a guide
wire lumen 44 which extends through a central lumen 138 (see FIGS. 6A and
6B) within intermediate member 40. Guide wire lumen 44 provides for the
passage and translation of a primary guide wire 48 which is used to
direct and guide distal portion 32 of the system to a target implant site
within the vasculature as well as to facilitate the positioning and
implantation of the distal end of the primary lumen of the implantable
device. The main body port 76 has a leur fitting similar to leur fitting
110 described above with respect to the side branch catheter control
hubs.

[0112]As is further illustrated in FIG. 4, a lever mechanism 56 extending
distally and downwardly from proximal handle portion 36a is provided for
steering distal catheter portion 32 of device 30 through the vasculature
into which it is positioned. This lever may be replaced by a rotating
control knob 193 in another handle embodiment 194 shown in FIG. 9. A
steering pull-wire, string or filament (not shown) is fixed to the
proximal end of lever 56 and extends through catheter portion 32 where
its distal end terminates and is attached within nose cone 46 of inner
member 42. Lever 56 is pivotally coupled within handle portion 36a such
that when rotated in a downward direction (indicated by arrow 65a of FIG.
4), the steering pull-wire is caused to be in a relaxed or slacken state.
Conversely, when lever 56 is rotated upward (indicated by arrow 65b), the
steering pull-wire is pulled or tensioned thereby causing the distal tip
of inner member 42, and thus the distal end of device 30, to bend. Any
number of steering pull-wires may be employed and selectively tensioned
to selectively articulate the distal end of device 30 in multiple
directions orthogonal to the longitudinal axis of the implantation
system. Typically, the subject delivery and deployment system will have
at least one, and often two to four distal points of articulation. These
articulation points may be at one or more distances from the distal end
of the catheter 32 in order to create compound curves of the distal end
of the catheter.

[0113]The relative positioning and interfacing of the implantable device
with the various catheters, lumens, guidewires, ports and pull-wires of
the subject implantation system will now be described with respect to
FIGS. 5A-6C, 6A and 6B. FIGS. 5A-5C illustrate an implantable device 120
partially deployed from the distal end 118 of outer sheath 38.
Implantable device 120 includes a main tubular body 122 and may include
one or more lateral tubular branches 124. At the distal tips of crowns or
apexes 126 of main body 122 and crowns or apexes 128 of side branch 124
may be eyelet loops 130 for receiving attachment strings 132 (shown only
in FIG. 5c). As is illustrated in FIG. 5c, when operatively loaded within
system 30 of FIG. 2A, the main lumen 122 of device 120 is longitudinally
disposed between outer sheath 38 and inner member 42 and is positioned
distally of the distal end 134 of intermediate member 40.

[0114]To load the implant device into outer sheath 38, the handle controls
are set to stretch the stent by extension of the distal tip 46 of the
inner member 42 relative to the distal end of the intermediate member.
When proximal and distal handle portions 36a and 36b are extended from
each other, shown in FIG. 8D, the main lumen of the stent is in a
stretched or tensioned condition. Conversely, when proximal and distal
handle portions 36a and 36b are unextended, as shown in FIG. 8E, the main
lumen of the stent is in an unstretched or untensioned condition. The
distal lumenal ends of inner member 42 and intermediate member 40 are
connection points for the string or strings which are releasably attached
to the distal and proximal stent main lumen openings 122. As discussed
above, the side branch stent distal lumenal end is releasably attached to
the distal end of the side branch catheter.

[0115]FIG. 6A shows a cross-section of a distal portion of implantation
system along the lines A-A of FIG. 5c, specifically, the cross-sectional
view is taken at the distal end of intermediate member 40. This view
shows the nested relationship between outer member 38, intermediate
member 40, inner member 42 which is positioned within central lumen 138
of intermediate member 40, and main guide wire 48 positioned within a
central guide wire lumen 44 of inner member 40 which extends distally
through tip 46.

[0116]Inner member 42 is a very small diameter catheter, for example, in
the range of 3 to 8 French for cardiovascular applications, and has, in
addition to central guide wire lumen 44, a plurality of attachment string
lumens 140 circumferentially disposed about central guide wire lumen 44
which serve to direct the alignment of the attachment strings to the
connection points on the distal end of the main stent lumen. Multiple
lumens 140 are located at the distal portion of member 42 and extend
along the entire length of the inner member 42. Lumens 140 may be in
communication with one or more flush ports at the handle portion of the
delivery system whereby saline may be flushed through lumens 140 at a
pressure greater than that of the surrounding blood flow to prevent blood
flow through the device lumens. Lumens 140 may also be used to deliver
radiopaque contrast dye used during fluoroscopically visualized placement
of the device. Lumens 140 and the exit ports 186, described below, allow
for visualization of the dye flowing through the implant at various
stages of deployment in order to verify that placement of the stent
yields a satisfactory flow pattern and therapeutic result.

[0117]In other embodiments, such as that illustrated in FIGS. 10A, 10B and
10C, attachment string lumens 140 may extend along only a portion of the
length of inner member 40, e.g., only a few millimeters distally to
proximally. This embodiment is particularly suitable in the case where
only one attachment string is employed with multiple stent connection
points. Here, the single string element exits one of the distal lumens,
is passed through the stent connection point, is passed distally to
proximally through another of the lumens, exits proximally from that
lumen and is passed through another of the lumens distally to proximally
and passed through another stent connection point. The interlacing
pattern continues until all stent connection points are laced with the
singular string which passes through the multiple circumferential lumens.
This configuration of attachment string lumens which extend only a
portion of the length of the inner member, may also be employed with the
intermediate member 40 and with the side branch catheters 94a, 94b, 94c.
With respect to an intermediate member employing such a string lumen
configuration, the proximal portion of intermediate member 40 would be a
single lumen containing the inner member 42 and the shorter
circumferential lumens would contain the side branch catheters as well as
the attachment wires for the proximal end of the main stent lumen. As
will be seen from this embodiment. and those discussed below, any
combination of lacing patterns may be used to attach an individual stent
end to the respective catheter to which it is attached.

[0118]Referring again to the embodiment FIG. 6A, the number of distal
attachment strings lumens 140 is double the number of attachment strings
132 where one pair of adjacent attachment strings lumens 140a, 140b is
provided for each distal attachment string 132. As such, where device 120
is fully loaded within the deployment system, the first portion of a
distal attachment string 132 resides within lumen 140a and a second or
return portion of the distal attachment string resides within lumen 140b.

[0119]In addition to attachment/deployment string lumens 140 are one or
more steering pull-wire lumens 142, the function of which is as described
above with respect to FIG. 4. Typically, one or two pairs of
diametrically opposed (180° apart) steering pull-wires are
employed to provide opposing orthogonal deflections of the distal end of
the delivery system. The greater the number of steering pull-wire pairs
employed, the greater the directions of steering in articulating the
delivery system.

[0120]In addition to central lumen 138 through which inner member 42 is
translated, intermediate member 40 includes a plurality of proximal
attachment string lumen pairs 146a, 146b where lumen 146a is shown
situated radially outward from lumen 146b. The attachment strings
attached to or threaded through the proximal crowns (not shown) of main
lumen 122 of device 120 utilize lumens 146. The number of proximal
attachment string lumens 146 is double the number of proximal attachment
strings where one pair of attachment string lumens 146a, 146b is provided
for each proximal attachment string, i.e., where device 120 is fully
loaded within the delivery and deployment system, the fixed-end portion
of a proximal attachment string resides within lumen 146a and the distal
or return portion of the proximal attachment string resides within lumen
146b.

[0121]In addition to attachment string lumens 146, intermediate member 40
also provides a plurality of lumens 148, also circumferentially disposed
about central lumen 138 and preferably interposed between pairs of
proximal attachment lumens 146, where one or more of the lumens 148 may
be employed to translate and deliver a side branch catheter 150 (shown in
FIG. 6A without detail). Side branch catheter 150 provides a central side
branch guide wire lumen 152 for delivering and translating a side branch
guide wire 154. Additional lumens 148 extending from a handle flush port
(not shown) may be provided for evacuating air from the delivery system
30. The additional lumens 148 may also allow for the rehydration of
tissue graft coverings or other coverings which need to be prepared with
solutions and potential therapeutic agents such as pharmacologics, stem
cells, or other agents. This allows the stent graft or other device to be
constrained in the delivery catheter in a dried dehydrated state
subsequently packaged, sterilized, and rehydrated by the flushing and
preparing the catheter at the time of use. Any unused lumens 148 provide
enhanced flexibility of the intermediate member, particularly where the
distal end of the device is deflectable at multiple articulation points.

[0122]FIGS. 7A, 7B and 7C illustrate various possible embodiments of side
branch catheters suitable for use with the delivery system of the present
invention. Side branch catheter 160 of FIG. 7A provides a central guide
wire lumen 162 and plurality of attachment string lumens 164 arranged
circumferentially about central lumen 162. Lumens 164 are utilized or
occupied by the attachment strings (not shown) which are looped or
threaded through the distal crowns 128 of side branch lumen 124 of device
120 (see FIG. 5A). The number of side branch attachment string lumens 164
is double the number of side branch attachment strings where one pair of
attachment string lumens 146a, 146b is provided for each side branch
attachment string, i.e., where device 120 is fully loaded within the
implantation system, the proximal portion of a side branch attachment
string resides within lumen 164a and tie distal or return portion of the
side branch attachment string resides within lumen 164b.

[0123]Side branch catheter 170 of FIG. 7B provides an outer member 172
having a central lumen 174 and an inner member 176 positioned
concentrically therein. Inner member 176 also has a central lumen 178 for
translating and delivering a side branch guide wire (not shown). Outer
member 172 further provides a plurality of side branch attachment string
lumens 180 where there is a one-to-one correspondence between the number
of side branch attachment string lumens 180 and the number of side branch
attachment strings (not shown). In this embodiment, the proximal portion
of side branch attachment strings reside within the space between the
internal diameter of outer member 172 and the external diameter of inner
member 176 and after being looped through the distal attachment eyelets,
crowns or cells, the distal or return portion of the strings pass through
lumens 180 of outer member 172.

[0124]In another embodiment of side branch catheter 200, shown in FIG. 7c
the side branch catheter can be composed of two concentric single lumens.
One single lumen tubing 202 defining an internal diameter and another
single lumen tubing 203 defining an outer diameter provides for the side
branch attachment strings to be contained within the space 201 between
the internal diameter of the outer tubing 202 and the outer diameter of
the inner tubing 203. The internal diameter of the inner tubing is used
to translate a guidewire (not shown) through side branch guidewire lumen
204 which is isolated from the attachment strings as shown in FIG. 7c.
This lumen configuration may also be employed with the intermediate and
inner members.

[0125]Referring to FIG. 6B, there is shown a cross-sectional view taken
along lines B-B of FIG. 5c, specifically through a proximal end of distal
tip 46 where inner member 42 terminates. Distal tip 46 provides the
distal portion of guide wire lumen 44 as well as the distal lumen
portions 182 of distal attachment string lumens 140 of inner member 42
where the plurality of distal lumen portions 182 are axially aligned and
have a one-to-one correspondence with inner member attachment string
lumens 140. As such, the same pairing of adjacent attachment string
lumens 182a, 182b is provided for each distal attachment string 132,
i.e., where the fixed-end portion of a distal attachment string 132
resides within lumen portion 182a and the releasable or return portion of
the distal attachment string resides within lumen portion 182b. As is
best illustrated in FIG. 6c, after passing within lumen portions 182a,
the attachment strings 132 are passed radially out of distal tip 46
through designated proximal side ports 184. The attachment strings are
then looped or threaded around eyelets 130 or crowns or apices 126 or
through the very distal cells of main lumen 122, and threaded back
through the designated side port 184 of distal tip 46 whereby they
re-enter respective lumen portions 182 and respective attachment string
lumens 140. As such, for every pair of attachment string lumens, there
are half as many side ports 184, i.e., there is a one-to-one
correspondence between the number of attachment strings 132 and the
number of distal tip side ports 184. Distal tip 46 also provides for
distal side ports 186 to facilitate the loading of strings during
assembly of the implant to the deliver system.

[0126]FIG. 16 illustrates a deployment system of the present invention in
which only a single string 135 is used to retain and deploy the distal
end (forward facing end) of implantable device 120. The basic components
of the system are comparable to those identified and described with
respect to FIGS. 5A-5C where like reference numbers refer to similar
components. Similar to the manner described with respect to FIGS. 10A-10C
above, the singular attachment/-deployment string 135 is passed through a
designated lumen (not shown) within guide wire catheter 42 and passed
radially out of distal tip 46 through a designated proximal side port
184. The attachment/deployment string 135 is then looped or threaded
through each of eyelets 130 (or through crowns or apices 126 or through
the very distal cells of main lumen 122), and threaded back through
another designated side port 184 of distal tip 46 whereby it re-enters
the string lumen. The string extends through the system to the proximal
end and is able to be fixed, released, tensioned, pulled, tightened, etc.
by a control mechanism as described above. In similar fashion, additional
strings may be used for attachment and deployment of the other lumenal
ends of the implantable device, where each lumenal end is controlled by a
separate string. With fewer strings, the complexity of fabricating and
operating the stent delivery system is greatly reduced. Additionally, the
necessary cross-sectional profile (i.e., diameter) of the system can be
minimized and, thus, applicable in smaller vessel applications.

[0127]As mentioned above, the deployment/attachment means of the subject
systems are not limited to strings and other tensionable elements, and
may include other means. An example of alternative stent
deployment/attachment means is provided with the delivery system 400 of
FIG. 17. System 400 includes a distal catheter portion 402 and a proximal
or handle portion 404.

[0128]Catheter portion 402 includes outer sheath 408 having one or more
lumens therein and within which an intermediate member 410 is
translatable there through. When operatively loaded within delivery
system 400, the main body of a stent 450 (shown in FIG. 18A) is received
between the luminal spacing between outer sheath 408 and intermediate
member 410. Intermediate member 410 defines a lumen through which an
inner member 416 (see FIG. 18B) is translated and which, in turn, defines
a lumen 424 through which the system guidewire 418 is deliverable. Inner
member 416 terminates at a conical distal tip 420 which facilitates
forward translation of the device through tortuous vasculature. Extending
from a proximal facing surface of conical tip 420 are extensions members
422, such as pins or hooks, which extend parallel to the longitudinal
axis of the system. The distal end 426 of intermediate member 410 may
define a receptacle or cup for receiving pins 422 so as to capture the
apices 428 of the distal end of the main stent lumen 450 when operatively
loaded within thereon (see FIG. 18A). The proximal end 412 of outer
sheath 408 provides branched luminal ports 412 to receive side branch
guidewires 425 as well as respective deployment members (e.g., strings)
427 for directing and deploying the side branch lumens of a branched
stent (not shown). The strings 427 may be controlled and tensioned by
mechanism as described above. Here, two ports 412 are provided for a
stent having two side branches, however, more or fewer ports may be
provided to accommodate stent's having any number of side branches. As
with the embodiments described above, internal valve mechanisms may be
provided to fluidly seal the luminal ports 412, thereby preventing
leakage of blood therefrom.

[0129]The proximal portion 404 of delivery and deployment system 400
includes handle portion 436 which may have proximal and distal portions
which are axially translatable axially with respect to each other, as
described above, to control the amount of extension and foreshortening
undergone by the main body of a stent operatively loaded within the
delivery system. Handle 436 provides a pair of controls including a knob
430 to which one end of the deployment/attachment member(s) (e.g.,
strings) for controlling the deployment of the proximal end of a stent
device is permanently anchored but which itself is removable from the
handle to manually pull the strings there through. A hemostatic valve may
be incorporated into the handle for preventing the back flow of fluid,
e.g., blood, out of the handle when the knob is removed therefrom. The
counter control is provided by dial or drive screw 432, which is used to
releasably anchor the free ends of the string or string set to the
handle. As described above with respect to the delivery system of FIGS.
2A and 2B, these control members are used in tandem to maintain a
constant tension on the attachment strings and keeping the implant
restrained at its proximal end within the delivery system while the
delivery system is being articulated through the vasculature.

[0130]FIGS. 18A and 18B illustrate the retention and deployment,
respectively, of a distal end of a main stent lumen 450 from system 400.
As mentioned previously, the apices 428 or the like of the stent cells at
the distal most end of the stent, when loaded, are synched or held
radially inward and are captured by the engagement of pins 422 of inner
member 416 and receptacle 426 of intermediate member 410, as illustrated
in FIG. 18A. The engagement of the pins within the receptacle may be
biased or spring-loaded such that, by operating a release mechanism, such
as by the depression of a button 434 on handle 436, inner member 416 is
caused to advance or spring forward so as to retract the pins 422 from
the receptacle and free the stent apices 428, as illustrated in FIG. 18B.
FIG. 19 illustrates a spring mechanism 452 within handle 436 which, when
compressed (as would be the case when the system is pre-loaded with the
stent), holds inner member 416 in a retracted position. When button 434
is depressed, spring 452 is released from its compressed condition and
causes inner member 416 to advance forward thereby releasing pins 422
from stent apices 428. Alternatively, the system may be configured such
that intermediate member 410 may be retracted to release the pins from
the receptacle 426.

[0131]Any type and combination of deployment\attachment members and
mechanisms may be used with the subject stent delivery systems, where
each end of the stent lumens is controlled by the same type of mechanism,
or one or more ends of the stent lumens may be retained and released by
one type of mechanism and one or more of the other stent ends may be
retained and released by another type of mechanism.

[0132]The deployment systems of the present invention may further provide
means for flushing the various lumens of the system. In particular, it is
important to flush the guidewire lumen in order to clear it of air prior
to inserting the system into the body. To this end, as illustrated in
FIG. 17, a flush port 438 is provided at the proximal end 442 of handle
404. Any source of flushing fluid, such as a syringe 440 shown in FIG.
17, may be used to inject fluid within flush port 428. Flush port 438 is
in fluid communication with guidewire lumen 424 of inner member 416 and
is thereby flushed by the fluid injected into it through port 438. The
injected fluid is caused to pass through lumen 424 and forces air and is
itself ejected out at the distal end of the lumen, as shown by arrows 445
in FIG. 17. At subsequent stages of the procedure, flush port 428 and
lumen 424 may be used to introduce radiographic dye in order to visualize
blood flow through the side branch arteries. In order to prevent backflow
of both the flushing fluid and blood that may enter the system during
use, gaskets or one-way valve may used within the system where suitable
to maintain hemostasis. For example, as illustrated in FIG. 20A, a gasket
444 is employed just distally of flush port 438 to prevent leakage
through the flush port. Additional gaskets, such as gaskets 446 and 448,
may be employed to provide hemostasis in the lumens leading to controls
430, 432.

[0133]Another optional feature of the present invention is to employ side
branch guidewires which also function embolic protection devices such as
those used during percutaneous transluminal angioplasty (PTA),
percutaneous transluminal coronary angioplasty (PTCA) and atherectomy
procedures. As shown in FIG. 23 guidewire 482 is equipped with a filter
mechanism 484 which is positioned at a downstream position within the
side branch artery prior to deployment of the side branch stent lumen.
Embolic material released as a result of the delivery or deployment of
the lumen is captured by filter 484.

[0134]The catheters and/or guidewires employed with the systems of the
present invention may include intravascular ultrasound (IVUS) imaging
capabilities where one or more miniaturized transducers are mounted on
the tip of a catheter or guidewire to provide electronic signals to an
external imaging system. Such a transducer array may rotate to produce an
image of the lumen of the artery showing the precise location of the take
offs for the connected branch vessels that will receive the connected
branch stents or other cavities into which the catheter is inserted, the
tissue of the vessel, and/or the tissue surrounding the vessel. In
addition to facilitating visualization during stent delivery and
deployment, such systems enhance the effectiveness of diagnosis and
treatment by providing important diagnostic (i.e., pre-stenting)
information, e.g., the location and size of an aneurysm, that is not
available from conventional x-ray angiography. Intravascular ultrasound
(IVUS) imaging catheters are commonly used as a preliminary step in the
procedure of selecting the appropriately sized stent graft before placing
a non-branched stent for several reasons which include to ensure that
coverage of a side branch vessel is not mistakenly done. Combining the
imaging ability into the tip of the stent delivery catheter has the
advantages of saving time by avoiding a catheter exchange. A second
technique which is commonly done to avoid the exchanging of the stent
delivery catheter and the IVUS catheter through the access site is to
gain another access point to introduce the separate IVUS catheter. By
integrating the IVUS transducers on the tip of the stent delivery
catheter, one eliminates the need for a second vascular access wound
should the imaging catheter have been delivered through a bilateral groin
access location. Also, when placing a stent inside another stent, an IVUS
catheter is used to ensure that the second stent will be deployed within
the lumen of the first stent in an overlapping fashion to extend the
coverage length of the treated region. In those cases, a first stent has
been placed and the downstream portion is free floating within a large
aneurysm sac and, as such, care must be taken to ensure that the second
stent to be placed within the first stent is not outside the lumen of the
first stent. To do otherwise, may result in unintentionally occluding the
vessel requiring the procedure to be converted to a surgery to remove the
misplaced second stent.

[0135]The system components of the present invention may alternatively or
additionally be provided with radiopaque markings to assist in
fluoroscopic imaging of the components during delivery and deployment of
the implants. FIGS. 24A and 24B illustrate the distal end of an outer
sheath 490 of a subject system in which radiopaque lines 494 have been
provided on the wall 492 of the sheath. In the illustrated embodiment,
two radiopaque lines 494 positioned 180° apart facilitate accurate
rotational orientation of the sheath within the vasculature. These lines
may also be used in conjunction with radiopaque markings provided on the
stent or graft portions of the implants whereby the markings on the
implant are aligned with those on the sheath to ensure proper orientation
of the implant, i.e., selectively positioning the side of the implant
having side branches adjacent the side of the delivery sheath which will
be in contact with the superior portion of the aortic arch. Examples of
stents having such radiopaque markings are disclosed in copending U.S.
Patent Application having Attorney Docket No. DUKEPZ01101.

[0136]The outer delivery sheaths employed with the delivery and deployment
systems of the present invention may be provided separately from the
remainder of the delivery catheters and configured to be positionable
over the assembly of catheter lumens. This may facilitate loading of the
stent, deployment strings and guidewires. As such, and as illustrated in
FIG. 25, the proximal end 504 of the sheath 500 may be equipped with a
hemostasis valve mechanism to prevent leakage. Another optional feature
of the sheath is that it may be fabricated with reinforced braiding 506
embedded within the wall 502 of the sheath, making it very kink-resistant
with high torquability. Additionally, by providing multiple spaced-apart
solder joints 508 with the braid along the length of the sheath, the
translational and rotational loads placed on the sheath during delivery
are distributed over more evenly over the length of the sheath, further
ensuring against kinking or bending of the sheath.

Methods of Device Implantation

[0137]An implantation procedure for certain of the subject devices will
now be described with respect to FIGS. 8A-8H and in the context of an
aortic arch application in which a stent-graft 2 of the present
invention, such as that illustrated in FIG. 1A, having a main body lumen
4 and three side branch lumens 6a, 6b and 6c, is percutaneously implanted
within the aortic arch 5, where, upon implantation, main body lumen 4
will reside within the aortic arch 5 and the three side branch lumens 6a,
6b and 6c will reside in the innominate artery 7a, the left common
carotid artery 7b and the left subclavian artery 7c, respectively, as
illustrated in FIG. 8H.

[0138]By means of a Seldinger technique via the left femoral artery 8, or
abdominal aortatomy, a main or aortic guide wire 48 is advanced through
the vasculature to the aortic arch 5 up to or until distal tip 48a is
caused to cross the aortic valve 10, as illustrated in FIG. 8A. Catheter
portion 32 of the implantation system 30 of the present invention,
provided with stent-graft 2 operatively loaded therein, is then
percutaneously introduced into the patient's body over guide wire 48.

[0139]It is noted that stent-grafts or stents otherwise covered with a
material, e.g., an ECM, may require reconstitution or hydration of the
graft or covering prior to commencing the implantation procedure. This
may be accomplished by flushing the guide wire lumen of delivery system
catheter with saline prior to inserting the catheter into the body.
Alternatively this could be done by rinsing in open air prior to
sheathing.

[0140]While stent graft 2 is in a loaded, undeployed state within catheter
portion 32, the delivery system's handle is in the retracted position,
i.e., proximal handle portion 34a and distal handle portion 34b are
engaged with each other. With the handle in the retracted position (shown
in FIGS. 8B and 8D), inner member 42 is held in a distally advanced
position and intermediate member 40 is held in a proximally retracted
position. This relative axial relationship between the intermediate and
inner members, maintains stent graft 2, or at least its main lumen 4, in
a stretched or tensioned condition. This is so as the distal crowns of
main lumen 4 are attached to the distal end of inner member 42, which in
turn is fixed to proximal handle portion 34a, and the proximal crowns of
main lumen 4 are attached to the distal end of intermediate member 40,
which in turn is fixed to the distal handle portion 36b.

[0141]Catheter portion 32 is then steered as necessary by means of
manipulating lever 56, thereby deflecting the distal tip of catheter 32,
as described above with respect to FIG. 4, and advanced into the
descending aorta and then into aortic arch 5. It is important that
catheter portion be properly rotationally positioned so that side branch
lumens 6a, 6b and 6c of stent graft 2 are substantially aligned with
arteries 7a, 7b and 7c, respectively, into which they are to be
delivered. To this end catheter 32 is torquable and fluoroscopic guidance
may be employed to further facilitate delivery of catheter portion 32. In
particular, fluoroscopic markers (not shown) on the crowns of the stent
graft lumens may be tracked and accurately positioned for optimal
placement within the respective arteries. The stent itself may be
radiopaque. The tip of the catheter will be radiopaque as well. A
steerable guidewire may be used to direct the main catheter 32 and the
side branch catheters as the stretched main stent body and side branch
stent bodies are steered by deflectable tipped guidewires placed into the
target implant site.

[0142]Throughout the delivery and deployment procedure, the various lumens
of catheter portion 32 may be continuously flushed with a fluid, e.g.,
saline or contrast agent, in a retrograde direction (relative to the
blood flow) at a pressure that is greater than or substantially equal to
the pressure of the arterial blood. This prevents possible leakage of
blood from the system as well as prevents any interference with the
functioning of the delivery process, particularly keeping the stent
strings lumens free and clear of blood, thereby eliminating clotting
within the lumens. Additionally, because each lumenal end of the stent
graft (i.e., the proximal and distal ends of main lumen 4 as well as the
distal ends of the side branch lumens) is individually controlled
(however, some or all may be collectively controlled) by the delivery and
deployment system 30 of the present invention, the interconnected cells
of the stent may be selectively elongated in an axially direction,
permitting the continual flow of blood around the device during
deployment within the anatomy. This axial elongation feature also permits
the implantation of larger diameter side branch stents within a vessel
having a smaller diameter.

[0143]Once the distal end of catheter portion 32 is operatively positioned
within the aortic arch 5, outer sheath 38 is retracted by manually
pulling on fitting 50 (see FIG. 3A) to expose the proximal end of nose
cone 46 of inner member 42 and to partially deploy the distal portion of
the main or aortic lumen 4 of stent graft 2 within the ascending aorta,
as shown in FIG. 8C. With partial deployment of stent graft 2, i.e., main
aortic lumen 4 is maintained in a stretched or tensioned state, arterial
blood flow exiting from aortic valve 10 flows through and around main
lumen 4. It is important to note that with main lumen 4 in this partially
deployed state, stent graft 2 can be easily repositioned within the
vasculature as it is not yet engaged with the vessel walls and, thus, is
not subject to the frictional resistance that contact with the walls
would cause, not to mention the avoidance of the resulting endothelial
damage and/or plaque embolization which is likely to occur.

[0144]While the various side branch lumens 6a, 6b and 6c of stent graft 4
may be deployed serially (one at a time) in any order or parallely
(simultaneously) together, it may be easiest to deploy the side branch
stent lumens one at a time in order from the most distally positioned
stent lumen (6a) to the most proximally positioned stent lumen (6a). This
deployment order eliminates unnecessary or repetitious translation of
outer sheath 38 over the stent graft, i.e., only gradual, unidirectional
(proximal) translation is necessary. This is advantageous in that
abrasions to the graft material are minimized, which is particularly
important when coated with a material, e.g., extra cellular matrix, or a
drug. This deployment order further reduces the necessary deployment
steps and, thus, the total time necessary for the implantation procedure.

[0145]To deploy a side branch stent lumen, such as stent lumen 6a, a side
branch guide wire 154 is inserted into (or may be preloaded within) side
branch port 110 of the respective control hub in its full distally
advanced position and into a lumen 152 of side branch catheter 150
positioned within lumen 148 of intermediate member 40 (see FIG. 6A). At
the same time, outer sheath 38 is incrementally and gradually retracted
proximally to allow the distal end of guide wire 154 to be translated
through side branch catheter 150, out its distal end and into innominate
artery 7a, as shown in FIG. 8C. The respective control hub 74 is then
distally translated along intermediate member 40 and may be fully engaged
with the associated catheter hub 84, thereby exerting maximum tension
being applied to the side branch stent cells by the attached attachment
strings and partially deploying side branch stent 6a as shown in 8D. Note
that the main body stent cells are being held stretched distal to
proximal through the relative positions of the inner member and
intermediate member as controlled by the handle in the close
configuration while the side branch stent is likewise maintained in a
stretched position by the distally advanced side branch catheter. This
procedure is repeated as necessary for the remaining number of side
branch stents, in this case, side branch stents 6b and 6c which are
delivered into the left common carotid artery 7b and the left subclavian
artery 7c, respectively, as illustrated in FIG. 8D. Note that at this
partially deployed state the blood flow is around the device as well as
through the implant depending on how tight and over what extension length
the attachment strings are pulled to the inner member exit ports 184. It
may be desirable to have just flow around the device and not through the
lumen of the device and that can be accomplished by cinching down on the
attachment strings on the distal end of main lumen to allow the most
minimal length of attachment thereby bringing the main lumen of
stentgraft to be held closed against distal tip 46 or inner member 42. It
is important to note that the distance between the distal main stent end
and its connection to the inner member is controllable by the length of
distal attachment strings which are controlled by the string clamp 70b by
adjusting and selecting the location of where the clamp locks onto the
distal attachment strings. This adjustment can be made in situ while the
stent is being delivered. Likewise the distance between the proximal main
stent end and its connection to the intermediate member is controllable
by the length of proximal attachment strings which are controlled by the
string clamp 72b by adjusting and selecting the location of where the
clamp locks onto the proximal attachment strings. This adjustment can be
made in situ while the stent is being delivered.

[0146]After placement within the branch arteries of all of the side branch
stents in their partially deployed states, the stent graft is ready for
full deployment. This is accomplished by moving the system handle to the
extended position, i.e., proximal handle portion 34a and distal handle
portion 34b are axially separated from each other, as illustrated in FIG.
8E. This action causes inner member 42 to translate proximally relative
to the fixed intermediate member 40 and in turn relaxes the tension
applied to the cells of main lumen 4, thereby bringing the lumen ends
closer together. As such, the stent foreshortens and there is a
corresponding increase in the diameter of main lumen 4, thereby securing
main lumen 4 against the walls of the aorta.

[0147]The side branch catheters are likewise translated proximally by
moving the respective control hub 74, 76, 78 a distance further from its
corresponding catheter hub 84, 86, 88 thereby relaxing the tension
applied to the cells of the side branch stent. As such there is a
corresponding increase in the diameter of side branch lumens 6a, 6b, 6c
as the lumenal ends foreshorten. It is important to note that the
distance between the stent ends and the catheter end is controllable by
adjusting the length of the strings traversing between the fixed-end knob
70a, 72a, 74a, 76a, 78a and the releasable end clamp 70b, 72b, 74b, 76b,
78b.

[0148]Once the stent cells have been released of their tension by the
translation of the catheter handle and side branch catheters, and as the
stent opens to a diameter which is expanded against the surrounding
artery wall, the entire blood flow enters through the distal end of the
device and exits all of its other lumens. Preferably, blood flow is
sealed from around the outside of the stentgraft once the stent has been
fully deployed.

[0149]While the stent itself may be fully deployed as shown in FIG. 8E, it
is still attached by attachment string sets to each of the distal ends of
inner member 42, intermediate member 40 and each side branch catheter
150a, 150b, 150c. The lumenal ends of the stent graft can now be detached
from their respective catheters. The stent graft's lumenal ends may be
released serially (one at a time) in any order or parallely
(simultaneously) together. As shown in FIG. 8F, the lumenal ends of the
side branch lumens 6b and 6c have been released, with the respective
attachment strings 190, side branch catheters 150a, 150b, 150c and side
branch guide wires 154 having been retracted. For each side branch
lumenal end, such as illustrated for side branch lumen 6a, catheter
detachment is accomplished by actuating the designated control clamp 74b,
76b and 78b on its respective catheter hub 74, 76, 78 to release the free
ends of strings 190 from the screw clamp of catheter hub and, at the same
time, by removing control knob 74a, 76a, 78a from the handle and pulling
strings 190 to the extent that the free ends unloop or detach from the
respective stent's crowns 128 of FIG. 8F. The strings 190 need only be
pulled until their free ends release the crowns but may be withdrawn
within the distal end of catheter portion 32.

[0150]As illustrated in FIG. 8G, a similar procedure is performed with
respect to deployment of the distal and proximal ends of main lumen 4,
where either end may be deployed first or both ends may be deployed
simultaneously The designated control clamp 70b, 72b is actuated to
release the free ends of strings 192 and, at the same time, control knobs
70a, 72a is removed from the handle thereby pulling strings 192 to the
extent that the free ends unloop or detach from the respective stent's
crowns 126. Strings 192 need only be pulled until their free ends release
the crowns but may be withdrawn within the distal end of catheter portion
32. The entirety of catheter portion 32 may then be removed from the
vasculature with stent graft 2 in a fully deployed state within the
aortic arch 5, as shown in FIG. 8H.

[0151]Referring now to FIG. 11, the partial deployment step of the above
described procedure is illustrated with respect to the delivery and
deployment of the implant 210 of FIG. 1E. Specifically, catheter portion
38 of the delivery system is positioned within the aorta with the distal
portion of main stent lumen 122 partially deployed within the aortic root
and ascending aorta 240, and side branch lumens 214a and 214b partially
deployed within the right and left coronary ostia 220 and 222,
respectively. A main guidewire 218 extends from catheter 38 and crosses
the former location of the natural aortic valve 224, while side branch
guidewires 226 and 228 extend within the coronary ostia 220, 222 from
side branch catheters 230 and 232, respectively. Upon release of the
attachment strings for the main lumen of the implant, prosthetic aortic
valve 216 will reside within the natural annulus 224. The side branch
lumens 214a, 214b may be deployed simultaneously with each other and with
main lumen 212, or serially in any order.

[0152]In any surgical or endovascular procedure, such as the one just
described, the fewer incisions made within the patient, the better. Of
course, this often requires highly specialized instrumentation and tools
used by a highly skilled surgeon or physician. In consideration of this,
the above-described single-incision device implantation procedure may be
modified to include the creation and use of one or more secondary
incisions to facilitate the initial delivery of the catheter portion 38
of the delivery system 32 at the implantation site and to further ensure
proper orientation of the stent graft upon its deployment at the site.

[0153]The two-incision (or multiple-incision) procedure of the present
invention involves a primary incision, e.g., a cut-down in the femoral
artery as described above, through which the above-described delivery and
deployment system is introduced into a first vessel within the body,
e.g., into the aortic arch, and a second incision (or more) at a
location(s) that provides access to at least one vessel which intersects
the first vessel, e.g., one of the side branches of the aortic arch. This
procedure is now described with reference to FIGS. 12A-12F and in the
context of implanting the stent graft 2 of the present invention in the
aortic arch by use of a primary incision made in the left femoral artery
8 to access the aortic arch 5 and a single secondary incision made in the
brachialcephalic or radial artery 15 to access one or more arteries of
the aortic tree.

[0154]First and second access incisions are made--in the left femoral
artery 8 and the left brachycephalic artery 15, respectively. By means of
a Seldinger technique, a secondary or "tether" guide wire 300 is advanced
through the left brachycephalic artery 15 into the innominate artery 7.
Guide wire 300 is then further advanced into the aortic arch 5, the
descending aorta 11, the abdominal aorta 13 and the left femoral artery 8
where it exits the body through the femoral incision, as illustrated in
FIG. 12A. A secondary or "tether" catheter 302 is then tracked over the
femoral end 300a of guide wire 300 and along the length of the guide wire
until catheter 302 is advanced out of the brachial incision, as
illustrated in FIG. 12B. Any suitable off-the-shelf system for
cardiovascular applications may be employed for use as the secondary or
tether guide wire and catheter. A dual lumen rapid-exchange (RX)
catheter, such as the one illustrated, having a second lumen positioned
at the proximal end of catheter 302. An advantage of an RX catheter is
that it only requires the string(s) (or a guidewire) to be pushed a
relatively short distance (requiring little "pushability") before it
exits the lumen rather than a greater distance in which the string would
be difficult to push due to its limp nature. Alternatively, the very end
of catheter 302 may be provided with a thru-hole or a cross-hole in the
catheter wall, as illustrated in FIG. 12C'.

[0155]The above descried implantation system 30 is then provided with
stent-graft 2 operatively loaded therein. For this procedure, as
illustrated in FIG. 12C, side branch attachment strings 190, or at least
one string thereof, for deploying the most distally located side branch
stent lumen 6a (i.e., the one intended for implantation into the
innominate artery 7a) and attached thereto (to one or more stent crowns)
are extended from side branch catheter 150a of primary or stent delivery
system catheter 38 and then threaded through a side branch tether tubing
35. The strings are then knotted 37a to prevent proximal withdrawal back
into catheter 150a and tubing 35. The remaining distal length of strings
190 are then threaded through the exchange lumen 304 of tether catheter
302. The ends of the strings are then knotted a second time 37b to
prevent proximal withdrawal of the strings from exchange lumen 304. With
the secondary catheter embodiment of FIG. 12C', the strings are threaded
into the main lumen 302 and out the side hole 305. The distal string ends
are then knotted 37b.

[0156]Secondary catheter 302, with side branch catheter 150a in tow as
well as the entirety of stent catheter 38 including primary or main guide
wire 48, is then advanced back through the femoral incision over
secondary guide wire 300 until catheter 302 is fully withdrawn from the
brachial incision, as illustrated in FIG. 12D, and until the distal end
of side branch catheter 150a is also extended from the brachial incision.
Tether guide wire 300 can now be removed from the body. At this point,
strings 190 are cut at a location 307 between the distal end of side
branch catheter 150a and the opposing end of secondary catheter 302 to
release the tether catheter 302 from the stent deployment system.

[0157]By the tension applied to strings 190 and the translation thereof,
side branch 6a of stent graft 4 has been drawn into the innominate artery
7a, as illustrated in FIG. 12E, in a partially deployed state (i.e.,
exposed but stretched). Concurrently, stent guide wire 48 is advanced
over the aortic arch 5 and across the aortic valve 10, thereby advancing
nose cone 46 and thus the distal end of the partially deployed (i.e.,
exposed but stretched or tensioned) main stent lumen 4 into the ascending
aorta. Meanwhile, stent catheter 38 has been tracked over stent guide
wire 48 into the aortic arch 5. Continued forward advancement of stent
catheter 38 is blocked by the partially deployed side branch lumen 6a. As
discussed above, with main lumen 4 maintained in a stretched or tensioned
state (as well as side branch lumen 6a), various advantages are provided:
arterial blood flow exiting from aortic valve 10 is allowed to flow to
the brain and body; repositioning of the stent graft 2 is possible, and
the likelihood of endothelial damage and/or plaque embolization from the
aortic wall is greatly minimized.

[0158]For stents and stent grafts having two or more side branch lumens
6a, 6b, 6c, as in FIG. 12F, the procedure described above and illustrated
in FIGS. 12A-12E with respect to the implantation of a stent having a
single side branch lumen is simultaneously performed, with separate
designated tether guide wires and catheters 150a, 150b, 150c. As
illustrated in FIG. 12F, with at least the distal end of the main stent
lumen 4 accurately positioned and partially deployed within the ascending
aorta, the respective side branch lumens 6a, 6b, 6c are deployed within
the innominate artery 7a, left common carotid artery 7b and the left
subclavian artery 7c, respectively. Alternatively, one or more of the
side branch lumens may be partially deployed as described with respect to
FIGS. 12A-12F, and the remaining side branch lumens, if any, may be
deployed in the manner described above with respect to FIGS. 8C and 8D.
Finally, with all side branch lumens 6a, 6b, 6c partially deployed within
their respective arteries, the procedural steps described with respect to
FIGS. 8E-8H may be performed to fully deploy the all lumens of the stent
graft and remove the delivery system from the body.

[0159]While the implants of the present invention have been described as
being deployable by stent restraining members or mechanisms, it is
understood that the subject implants may be configured such that they
and/or their lumenal ends are configured for deployment by an expandable
member or members. For example, each of the ends of the implant (i.e., of
the main lumen and of the side branch lumen(s)), in a loaded, undeployed
state, may be coupled to one or more of the nested catheters by placement
about an expandable balloon affixed to the catheter(s) The balloons, in
either a partially or fully expanded state, provide a sufficiently snug
fit with the implant ends such that the lumens of the implant may be
selectively stretched or tensioned along their lengths when manipulating
the catheter components.

[0160]The preceding merely illustrates the principles of the invention. It
will be appreciated that those skilled in the art will be able to devise
various arrangements which, although not explicitly described or shown
herein, embody the principles of the invention and are included within
its spirit and scope. Furthermore, all examples and conditional language
recited herein are principally intended to aid the reader in
understanding the principles of the invention and the concepts
contributed by the inventors to furthering the art, and are to be
construed as being without limitation to such specifically recited
examples and conditions. Moreover, all statements herein reciting
principles, aspects, and embodiments of the invention as well as specific
examples thereof, are intended to encompass both structural and
functional equivalents thereof. Additionally, it is intended that such
equivalents include both currently known equivalents and equivalents
developed in the future, i.e., any elements developed that perform the
same function, regardless of structure. The scope of the present
invention, therefore, is not intended to be limited to the exemplary
embodiments shown and described herein. Rather, the scope and spirit of
present invention is embodied by the appended claims.

[0161]It must be noted that as used herein and in the appended claims, the
singular forms "a", "an", and "the" include plural referents unless the
context clearly dictates otherwise. Thus, for example, reference to "a
string" may include a plurality of such strings and reference to "the
tubular member" includes reference to one or more tubular members and
equivalents thereof known to those skilled in the art, and so forth.

[0162]Where a range of values is provided, it is understood that each
intervening value, to the tenth of the unit of the lower limit unless the
context clearly dictates otherwise, between the upper and lower limits of
that range is also specifically disclosed. Each smaller range between any
stated value or intervening value in a stated range and any other stated
or intervening value in that stated range is encompassed within the
invention. The upper and lower limits of these smaller ranges may
independently be included or excluded in the range, and each range where
either, neither or both limits are included in the smaller ranges is also
encompassed within the invention, subject to any specifically excluded
limit in the stated range. Where the stated range includes one or both of
the limits, ranges excluding either or both of those included limits are
also included in the invention.

[0163]All publications mentioned herein are incorporated herein by
reference to disclose and describe the methods and/or materials in
connection with which the publications are cited. The publications
discussed herein are provided solely for their disclosure prior to the
filing date of the present application. Nothing herein is to be construed
as an admission that the present invention is not entitled to antedate
such publication by virtue of prior invention. Further, the dates of
publication provided may be different from the actual publication dates
which may need to be independently confined.